Signs and symptoms are the observed or detectable signs, and experienced symptoms of an
illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showing on a
medical scan. A symptom is something out of the ordinary that is experienced by an individual such as feeling feverish, a headache or other pain or pains in the body.
Signs and symptoms
Signs
A medical sign is an
objective observable indication of a disease, injury, or abnormal physiological state that may be detected during a
physical examination, examining the patient history, or diagnostic procedure.
These signs are visible or otherwise detectable such as a
rash or
bruise. Medical signs, along with
symptom
Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showi ...
s, assist in formulating diagnostic hypothesis. Examples of signs include
elevated blood pressure,
nail clubbing of the fingernails or toenails, staggering
gait, and
arcus senilis and arcus juvenilis of the eyes.
Indications
A ''sign'' is different from an "''
indication
Indication may refer to:
* A synonym for sign
* Human interface, highlighting the single object pointed to as a cursor is moved, without any other user action such as clicking, is indication
* Indication (medicine). A valid reason to use a certain ...
''" – the activity of a condition 'pointing to' (thus "indicating") a remedy, not the reverse (viz., it is not a remedy 'pointing to' a condition) – which is a specific reason for using a particular
treatment.
Symptoms
A symptom is something felt or experienced, such as pain or dizziness. Signs and symptoms are not mutually exclusive, for example a subjective feeling of fever can be noted as sign by using a thermometer that registers a high reading.
Cardinal signs and symptoms
Cardinal signs and symptoms are specific even to the point of being
pathognomonic Pathognomonic (rare synonym ''pathognomic'') is a term, often used in medicine, that means "characteristic for a particular disease". A pathognomonic sign is a particular sign whose presence means that a particular disease is present beyond any dou ...
. A cardinal sign or cardinal symptom can also refer to the major sign or symptom of a disease.
Abnormal
reflex
In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a stimulus.
Reflexes are found with varying levels of complexity in organisms with a nervous system. A reflex occurs ...
es can indicate problems with the
nervous system
In Biology, biology, the nervous system is the Complex system, highly complex part of an animal that coordinates its Behavior, actions and Sense, sensory information by transmitting action potential, signals to and from different parts of its ...
. Signs and symptoms are also applied to physiological states outside the context of disease, as for example when referring to the
signs and symptoms of pregnancy
Signs and symptoms of pregnancy are common, benign conditions that result from the changes to the body that occur during pregnancy. Signs and symptoms of pregnancy typically change as pregnancy progresses, although several symptoms may be present ...
, or the symptoms of
dehydration. Sometimes a disease may be present without showing any signs or symptoms when it is known as being
asymptomatic
In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered as ...
.
The disorder may be discovered through tests including scans. An
infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable d ...
may be asymptomatic which may still be
transmissible.
Signs vs. symptoms
Signs are different from experienced symptoms. A sign of a disorder is something that may be observed by another or detected during a medical examination or procedure.
For example
high blood pressure
Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high b ...
may be noted as a sign during an examination for which there have been no reported symptoms. A symptom is something experienced and reportable by a person such as a
headache
Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches.
Headaches can occur as a resul ...
or
fatigue
Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...
. Signs and symptoms may overlap, such as a bloody nose, which the individual experiences as unusual (symptom) and which others observe (sign).
The
CDC lists various diseases by their signs and symptoms such as for
measles which includes a high fever,
conjunctivitis
Conjunctivitis, also known as pink eye, is inflammation of the outermost layer of the white part of the eye and the inner surface of the eyelid. It makes the eye appear pink or reddish. Pain, burning, scratchiness, or itchiness may occur. The ...
, and
cough
A cough is a sudden expulsion of air through the large breathing passages that can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three ph ...
, followed a few days later by the measles
rash.
Syndrome
Signs and symptoms are often non-specific, but some combinations can be suggestive of certain
diagnoses, helping to narrow down what may be wrong. A particular set of characteristic signs and symptoms that may be associated with a disorder is known as a
syndrome. In cases where the underlying cause is known the syndrome is named as for example
Down syndrome
Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with child development, physical growth delays, mild to moderate ...
and
Noonan syndrome. Other syndromes such as
acute coronary syndrome may have a number of possible causes.
Terms
When a disease is evidenced by symptoms it is known as symptomatic. There are many conditions including
subclinical infections that display no symptoms, and these are termed
asymptomatic
In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered as ...
. Signs and symptoms may be mild or severe, brief or longer-lasting when they may become reduced (
remission
Remission often refers to:
*Forgiveness
Remission may also refer to:
Healthcare and science
*Remission (medicine), the state of absence of disease activity in patients with a chronic illness, with the possibility of return of disease activity
*R ...
), or then recur (
relapse
In internal medicine, relapse or recidivism is a recurrence of a past (typically medical) condition. For example, multiple sclerosis and malaria often exhibit peaks of activity and sometimes very long periods of dormancy, followed by relapse or ...
or
recrudescence) known as a
flare-up. A flare-up may show more severe symptoms.
The term
chief complaint The chief complaint, formally known as CC in the medical field, or termed presenting complaint (PC) in Europe and Canada, forms the second step of medical history taking. It is sometimes also referred to as reason for encounter (RFE), presenting pr ...
, also "presenting problem", is used to describe the initial concern of an individual when seeking medical help, and once this is clearly noted a
history of the present illness
Following the chief complaint in medical history taking, a history of the present illness (abbreviated HPI) (termed history of presenting complaint (HPC) in the UK) refers to a detailed interview prompted by the chief complaint or presenting sym ...
may be taken. The symptom that ultimately leads to a
diagnosis
Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engin ...
is called a cardinal symptom.Some symptoms can be misleading as a result of
referred pain, where for example a pain in the right shoulder may be due to
an inflamed gallbladder and not to presumed muscle strain.
[Greenberger N.J., Paumgartner G (2012). Chapter 311. Diseases of the Gallbladder and Bile Ducts. In Longo D.L., Fauci A.S., Kasper D.L., Hauser S.L., Jameson J, Loscalzo J (Eds), Harrison's Principles of Internal Medicine, 18e]
Prodrome
Many diseases have an early
prodromal stage where a few signs and symptoms may suggest the presence of a disorder before further specific symptoms may emerge.
Measles for example has a prodromal presentation that includes a hacking cough, fever, and
Koplik's spots in the mouth.
Over half of
migraine
Migraine (, ) is a common neurological disorder characterized by recurrent headaches. Typically, the associated headache affects one side of the head, is pulsating in nature, may be moderate to severe in intensity, and could last from a few ho ...
episodes have a prodromal phase.
Schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social wi ...
has a notable prodromal stage,
as has
dementia
Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...
.
Nonspecific symptoms
Nonspecific symptoms are very general and thus can be associated with a wide range of conditions. In other words, they are not specific to (not particular to) any one condition. Most signs and symptoms are at least ''somewhat'' nonspecific, as only
pathognomonic Pathognomonic (rare synonym ''pathognomic'') is a term, often used in medicine, that means "characteristic for a particular disease". A pathognomonic sign is a particular sign whose presence means that a particular disease is present beyond any dou ...
ones are ''highly'' specific. But certain nonspecific signs and symptoms are ''especially'' nonspecific and especially common. They are also known as constitutional symptoms when they affect the sense of well-being. They include unexplained weight loss, headache, pain, fatigue, loss of appetite, night sweats, and malaise.
Vital signs
Vital signs are the four signs that can give an immediate measurement of the body's overall functioning and health status. They are
temperature
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer.
Thermometers are calibrated in various temperature scales that historically have relied on ...
,
heart rate
Heart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and e ...
,
breathing rate, and
blood pressure
Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressur ...
. The
ranges
In the Hebrew Bible and in the Old Testament, the word ranges has two very different meanings.
Leviticus
In Leviticus 11:35, ranges probably means a cooking furnace for two or more pots, as the Hebrew word here is in the dual number; or perhaps ...
of these measurements vary with age, weight, gender and with general health.
A digital application has been developed for use in clinical settings that measures three of the vital signs (not temperature) using just a
smartphone
A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, whic ...
, and has been approved by
NHS England
NHS England, officially the NHS Commissioning Board, is an executive non-departmental public body of the Department of Health and Social Care. It oversees the budget, planning, delivery and day-to-day operation of the commissioning side of th ...
. The application is registered as ''Lifelight First'', and ''Lifelight Home'' is under development (2020) for monitoring-use by people at home using just the camera on their smartphone or tablet. This will additionally measure
oxygen saturation and
atrial fibrillation. Other devices are then not needed.
Syndromes
Many conditions are indicated by a group of known signs, or signs and symptoms. These can be a group of three known as a triad: a group of four known as a tetrad, and a group of five known as a petrad. An example of a triad is
Meltzer's triad
Meltzer's triad describes the classical symptoms suggesting the diagnosis of cryoglobulinaemia of polyclonal CGs seen in essential-, viral-, or connective tissue disease-associated cryoglobulinaemia. The triad consists of:
* palpable purpura
* arth ...
presenting
purpura a rash,
arthralgia painful joints, and
myalgia painful and weak muscles. Meltzer's triad indicates the condition
cryoglobulinemia.
Huntington's disease
Huntington's disease (HD), also known as Huntington's chorea, is a neurodegenerative disease that is mostly inherited. The earliest symptoms are often subtle problems with mood or mental abilities. A general lack of coordination and an uns ...
is a
neurodegenerative disease that is characterized by a triad of motor, cognitive, and psychiatric signs and symptoms.
A large number of these groups that can be characteristic of a particular disease are known as a
syndrome.
Noonan syndrome for example, has a diagnostic set of unique facial and musculoskeletal features.
Some syndromes such as
nephrotic syndrome may have a number of underlying causes that are all related to diseases that affect the
kidney
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; bloo ...
s.
Sometimes a child or young adult may have symptoms suggestive of a
genetic disorder
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorde ...
that cannot be
identified even after
genetic testing. In such cases the term
SWAN
Swans are birds of the family Anatidae within the genus ''Cygnus''. The swans' closest relatives include the geese and ducks. Swans are grouped with the closely related geese in the subfamily Anserinae where they form the tribe Cygnini. Sometim ...
(syndrome without a name) may be used. Often a diagnosis may be made at some future point when other more specific symptoms emerge but many cases may remain undiagnosed. The inability to diagnose may be due to a unique combination of symptoms or an overlap of conditions, or to the symptoms being atypical of a known disorder, or to the disorder being extremely rare.
Positive and negative
Sensory symptoms can also be described as positive symptoms, or as negative symptoms depending on whether the symptom is abnormally present such as tingling or itchiness, or abnormally absent such as
loss of smell
Anosmia, also known as smell blindness, is the loss of the ability to detect one or more smells. Anosmia may be temporary or permanent. It differs from hyposmia, which is a decreased sensitivity to some or all smells.
Anosmia can be due to a num ...
. The following terms are used for negative symptoms –
hypoesthesia is a partial loss of sensitivity to moderate stimuli, such as pressure, touch, warmth, cold.
Anesthesia
Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), a ...
is the complete loss of sensitivity to stronger stimuli, such as pinprick.
Hypoalgesia (analgesia) is loss of sensation to painful stimuli.
Symptoms are also grouped in to negative and positive for some
mental disorder
A mental disorder, also referred to as a mental illness or psychiatric disorder, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. Such features may be persistent, relapsing and remitti ...
s such as
schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social wi ...
.
Positive symptoms are those that are present in the disorder and are not normally experienced by most individuals and reflects an excess or distortion of normal functions.
[Understanding Psychosis](_blank)
, Mental Health Illness of Australia. Examples are
hallucinations
A hallucination is a perception in the absence of an external stimulus that has the qualities of a real perception. Hallucinations are vivid, substantial, and are perceived to be located in external objective space. Hallucination is a combinati ...
,
delusions, and bizarre behavior.
Negative symptoms are functions that are normally found but that are diminished or absent such as
apathy
Apathy is a lack of feeling, emotion, interest, or concern about something. It is a state of indifference, or the suppression of emotions such as concern, excitement, motivation, or passion. An apathetic individual has an absence of inter ...
and
anhedonia.
Neuropsychiatric
Neuropsychiatric symptoms are present in many
degenerative disorder
Degenerative disease is the result of a continuous process based on degenerative cell changes, affecting tissues or organs, which will increasingly deteriorate over time.
In neurodegenerative diseases, cells of the central nervous system stop wor ...
s including
dementia
Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...
, and
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ...
. Symptoms commonly include
apathy
Apathy is a lack of feeling, emotion, interest, or concern about something. It is a state of indifference, or the suppression of emotions such as concern, excitement, motivation, or passion. An apathetic individual has an absence of inter ...
,
anxiety
Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil
Turmoil may refer to:
* ''Turmoil'' (1984 video game), a 1984 video game released by Bug-Byte
* ''Turmoil'' (2016 video game), a 2016 indie oil tycoon video ...
, and
depression.
Neurological and psychiatric symptoms are also present in some
genetic disorder
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorde ...
s such as
Wilson's disease.
Executive dysfunction is an often found symptom in many disorders including
schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social wi ...
, and
ADHD.
Radiologic
Radiologic signs are abnormal
medical findings
Medical findings are the collective physical and psychological occurrences of patients surveyed by a medical doctor. The survey is composed of physical examinations by the doctor's senses and simple medical devices, which build clinical findings.
...
on
imaging scanning. These include the
Mickey Mouse sign and the
Golden S sign. When using imaging to find the cause of a complaint, another unrelated finding may be found known as an
incidental finding Incidental medical findings are previously undiagnosed medical or psychiatric conditions that are discovered unintentionally and during evaluation for a medical or psychiatric condition. Such findings may occur in a variety of settings, including ro ...
.
Cardinal
Cardinal signs and symptoms are those that may be diagnostic, and
pathognomonic Pathognomonic (rare synonym ''pathognomic'') is a term, often used in medicine, that means "characteristic for a particular disease". A pathognomonic sign is a particular sign whose presence means that a particular disease is present beyond any dou ...
– of a certainty of diagnosis.
Inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...
for example has a recognised group of cardinal signs and symptoms,
as does
exacerbations of chronic bronchitis, and
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ...
.
In contrast to a pathognomonic cardinal sign, the absence of a sign or symptom can often rule out a condition. This is known by the Latin term ''
sine qua non
''Sine qua non'' (, ) or ''condicio sine qua non'' (plural: ''condiciones sine quibus non'') is an indispensable and essential action, condition, or ingredient. It was originally a Latin legal term for " conditionwithout which it could not be" ...
''. For example, the absence of known genetic mutations
specific for a
hereditary disease would rule out that disease.
Another example is where the
vaginal pH
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hy ...
is less than 4.5, a diagnosis of
bacterial vaginosis
Bacterial vaginosis (BV) is a disease of the vagina caused by excessive growth of bacteria. Common symptoms include increased vaginal discharge that often smells like fish. The discharge is usually white or gray in color. Burning with urinatio ...
would be excluded.
Reflexes
A
reflex
In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a stimulus.
Reflexes are found with varying levels of complexity in organisms with a nervous system. A reflex occurs ...
is an automatic response in the body to a stimulus.
Its absence, reduced (hypoactive), or exaggerated (hyperactive) response can be a sign of damage to the
central nervous system
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all p ...
or
peripheral nervous system
The peripheral nervous system (PNS) is one of two components that make up the nervous system of bilateral animals, with the other part being the central nervous system (CNS). The PNS consists of nerves and ganglia, which lie outside the brain a ...
. In the
patellar reflex (knee-jerk) for example, its reduction or absence is known as
Westphal's sign and may indicate damage to
lower motor neurons. When the response is exaggerated damage to the
upper motor neurons
Upper motor neurons (UMNs) is a term introduced by William Gowers in 1886. They are found in the cerebral cortex and brainstem and carry information down to activate interneurons and lower motor neurons, which in turn directly signal muscles t ...
may be indicated.
Facies
A number of
medical conditions are associated with a distinctive facial expression or appearance known as a
facies An example is
elfin facies which has facial features like those of the
elf, and this may be associated with
Williams syndrome, or
Donohue syndrome. The most well-known facies is probably the
Hippocratic facies
The Hippocratic facies ( la, facies Hippocratica, links=no) is the change produced in the face recognisable as a medical sign known as facies and prognostic of death. It may also be seen as due to long illness, excessive defecation, or excessive h ...
that is seen on a person as they near death.
Anamnestic signs
Anamnestic signs (from ''anamnēstikós'', ἀναμνηστικός, "able to recall to mind") are signs that indicate a past condition, for example paralysis in an arm may indicate a past
stroke.
Asymptomatic
Some diseases including
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...
s, and infections may be present but show no signs or symptoms
and these are known as
asymptomatic
In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered as ...
.
A gallstone may be asymptomatic and only discovered as an
incidental finding Incidental medical findings are previously undiagnosed medical or psychiatric conditions that are discovered unintentionally and during evaluation for a medical or psychiatric condition. Such findings may occur in a variety of settings, including ro ...
.
Easily spreadable viral infections such as
COVID-19
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease quickl ...
may be asymptomatic but may still be
transmissible.
History
Symptomatology
A symptom (from
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
σύμπτωμα, "accident, misfortune, that which befalls", from συμπίπτω, "I befall", from συν- "together, with" and πίπτω, "I fall") is a departure from normal function or feeling. Symptomatology (also called semiology) is a branch of
medicine
Medicine is the science and Praxis (process), practice of caring for a patient, managing the diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, and Health promotion ...
dealing with the signs and symptoms of a disease.
This study also includes the
indications of a
disease
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
. It was first described as
semiotics
Semiotics (also called semiotic studies) is the systematic study of sign processes (semiosis) and meaning making. Semiosis is any activity, conduct, or process that involves signs, where a sign is defined as anything that communicates something, ...
by
Henry Stubbe in 1670 a term now used for the study of
sign communication.
Prior to the nineteenth century there was little difference in the powers of observation between physician and patient. Most medical practice was conducted as a co-operative interaction between the physician and patient; this was gradually replaced by a "monolithic consensus of opinion imposed from within the community of medical investigators".
[Jewson, N.D.,]
Medical Knowledge and the Patronage System in 18th Century England
", ''Sociology'', Vol. 8, No. 3 (1974), pp. 369–85.[Jewson, N.D.,]
The Disappearance of the Sick Man from Medical Cosmology, 1770–1870
", ''Sociology'', Vol. 10, No. 2, (1976), pp. 225–44. Whilst each noticed much the same things, the physician had a more informed interpretation of those things: "the physicians knew what the findings meant and the layman did not".
Development of medical testing
A number of advances introduced mostly in the 19th century, allowed for more objective assessment by the physician in search of a diagnosis, and less need of input from the patient.
During the 20th century the introduction of a wide range of
imaging
Imaging is the representation or reproduction of an object's form; especially a visual representation (i.e., the formation of an image).
Imaging technology is the application of materials and methods to create, preserve, or duplicate images.
...
techniques have made a huge impact on diagnostic capability. Other developments in the field of
genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar worki ...
,
medical biochemistry
Clinical chemistry (also known as chemical pathology, clinical biochemistry or medical biochemistry) is the area of chemistry that is generally concerned with analysis of bodily fluids for diagnostic and therapeutic purposes. It is an applied ...
, and
molecular diagnostics have also played major roles.
* In 1761 the
percussion
A percussion instrument is a musical instrument that is sounded by being struck or scraped by a beater including attached or enclosed beaters or rattles struck, scraped or rubbed by hand or struck against another similar instrument. Exc ...
technique for diagnosing respiratory conditions was discovered by
Leopold Auenbrugger
Josef Leopold Auenbrugger or Avenbrugger (19 November 1722 – 17 May 1809), also known as Leopold von Auenbrugger, was an Austrian physician who invented percussion as a diagnostic technique. On the strength of this discovery, he is con ...
.
This method of tapping body cavities to note any abnormal sounds had already been in practice for a long time in cardiology.
[ Percussion of the thorax became more widely known after 1808 with the translation of Auenbrugger's work from Latin into French by Jean-Nicolas Corvisart.
* In 1819 the introduction of the stethoscope by René Laennec began to replace the centuries-old technique of immediate auscultation – listening to the heart by placing the ear directly on the chest, with mediate auscultation using the stethoscope to listen to the sounds of the heart and respiratory tract. Laennec's publication was translated into English, 1821–1834, by John Forbes
* The 1846 introduction by surgeon John Hutchinson (1811–1861) of the spirometer, an apparatus for assessing the mechanical properties of the lungs via measurements of forced exhalation and forced inhalation. (The recorded lung volumes and air flow rates are used to distinguish between restrictive disease (in which the lung volumes are decreased: e.g., ]cystic fibrosis
Cystic fibrosis (CF) is a rare genetic disorder that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine. Long-term issues include difficulty breathing and coughing up mucus as a result of frequent lung infections. ...
) and obstructive diseases (in which the lung volume is normal but the air flow rate is impeded; e.g., emphysema
Emphysema, or pulmonary emphysema, is a lower respiratory tract disease, characterised by air-filled spaces ( pneumatoses) in the lungs, that can vary in size and may be very large. The spaces are caused by the breakdown of the walls of the a ...
).)
* The 1851 invention by Hermann von Helmholtz
Hermann Ludwig Ferdinand von Helmholtz (31 August 1821 – 8 September 1894) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. The Helmholtz Associatio ...
(1821–1894) of the ophthalmoscope, which allowed physicians to examine the inside of the human eye.
* The () immediate widespread clinical use of Sir Thomas Clifford Allbutt's (1836–1925) six-inch (rather than twelve-inch) pocket clinical thermometer, which he had devised in 1867.[Allbutt, T.C., "Medical Thermometry", British and Foreign Medico-Chirurgical Review]
Vol. 45, No. 90, (April 1870), pp. 429–41
Vol. 46, No. 91, (July 1870), pp. 144–56.
/ref>
* The 1882 introduction of bacterial cultures by Robert Koch, initially for tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in w ...
, being the first laboratory test to confirm bacterial infections.
* The 1895 clinical use of X-ray
X-rays (or rarely, ''X-radiation'') are a form of high-energy electromagnetic radiation. In many languages, it is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it in 1895 and named it ' ...
s which began almost immediately after they had been discovered that year by Wilhelm Conrad Röntgen (1845–1923).
* The 1896 introduction of the sphygmomanometer
A sphygmomanometer ( ), a blood pressure monitor, or blood pressure gauge, is a device used to measure blood pressure, composed of an inflatable cuff to collapse and then release the artery under the cuff in a controlled manner, and a mercury or ...
, designed by Scipione Riva-Rocci (1863–1937), to measure blood pressure
Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressur ...
.
Diagnosis
The recognition of signs, and noting of symptoms may lead to a diagnosis. Otherwise a physical examination may be carried out, and a medical history
The medical history, case history, or anamnesis (from Greek: ἀνά, ''aná'', "open", and μνήσις, ''mnesis'', "memory") of a patient is information gained by a physician by asking specific questions, either to the patient or to other pe ...
taken. Further diagnostic medical tests such as blood test
A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or via fingerprick. Multiple tests for specific blood components, such as a glucose test or a ch ...
s, scans, and biopsies, may be needed. An X-ray
X-rays (or rarely, ''X-radiation'') are a form of high-energy electromagnetic radiation. In many languages, it is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it in 1895 and named it ' ...
for example would soon be diagnostic or not of a bone fracture. A noted significance detected during an examination or from a medical test may be known as a medical finding.
Examples of signs and symptoms
* Ascites
* Nail clubbing (deformed nails)
* Cough
A cough is a sudden expulsion of air through the large breathing passages that can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three ph ...
* Death rattle
Terminal respiratory secretions (or simply terminal secretions),, known colloquially as a death rattle, are sounds often produced by someone who is near death as a result of fluids such as saliva and Bronchus, bronchial secretions accumulating in ...
(last moments of life)
* Hemoptysis
Hemoptysis is the coughing up of blood or blood-stained mucus from the bronchi, larynx, trachea, or lungs. In other words, it is the airway bleeding. This can occur with lung cancer, infections such as tuberculosis, bronchitis, or pneumonia ...
(blood-stained sputum)
* Jaundice
Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme met ...
* Organomegaly an enlarged organ such as the liver
The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...
(hepatomegaly
Hepatomegaly is the condition of having an enlarged liver. It is a non-specific medical sign having many causes, which can broadly be broken down into infection, hepatic tumours, or metabolic disorder. Often, hepatomegaly will present as an ab ...
)
* Palmar erythema (reddening of hands)
* Hypersalivation excessive (saliva)
* Unintentional weight loss
See also
* Biomarker (medicine)
* Focal neurologic signs
References
{{DEFAULTSORT:Medical Sign
Symptoms