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 ...

, a contraindication is a condition (a situation or factor) that serves as a reason not to take a certain medical treatment due to the harm that it would cause the patient. Contraindication is the opposite of

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 ...

, which is a reason to use a certain treatment. Absolute contraindications are contraindications for which there are no reasonable circumstances for undertaking a course of action (that is, overriding the prohibition). For example: * Children and teenagers with viral infections should not be given

aspirin Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat in ...

because of the risk of

Reye syndrome Reye syndrome is a rapidly worsening brain disease. Symptoms of Reye syndrome may include vomiting, personality changes, confusion, seizures, and loss of consciousness. While liver toxicity typically occurs in the syndrome, jaundice usually doe ...

. * A person with an

anaphylactic Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the follow ...

food allergy A food allergy is an abnormal immune response to food. The symptoms of the allergic reaction may range from mild to severe. They may include itchiness, swelling of the tongue, vomiting, diarrhea, hives, trouble breathing, or low blood pressur ...

should never eat the food to which they are allergic. * A person with

hemochromatosis Iron overload or hemochromatosis (also spelled ''haemochromatosis'' in British English) indicates increased total accumulation of iron in the body from any cause and resulting organ damage. The most important causes are hereditary haemochromatos ...

should not be administered iron preparations. * Some medications are so

teratogenic Teratology is the study of abnormalities of physiological development in organisms during their life span. It is a sub-discipline in medical genetics which focuses on the classification of congenital abnormalities in dysmorphology. The relat ...

that they are absolutely contraindicated in pregnancy; examples include

thalidomide Thalidomide, sold under the brand names Contergan and Thalomid among others, is a medication used to treat a number of cancers (including multiple myeloma), graft-versus-host disease, and a number of skin conditions including complications o ...

and

isotretinoin Isotretinoin, also known as 13-''cis''-retinoic acid and sold under the brand name Accutane among others, is a medication primarily used to treat severe acne. It is also used to prevent certain skin cancers ( squamous-cell carcinoma), and in ...

. Relative contraindications are contraindications for circumstances in which the patient is at higher risk of complications from treatment, but these risks may be outweighed by other considerations or mitigated by other measures. For example, a pregnant person should normally avoid getting

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, but the risk from

radiography Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeuti ...

may be outweighed by the benefit of diagnosing (and then treating) a serious condition such as

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 ...

. Another principal pair of terms for ''relative contraindications'' versus ''absolute contraindications'' is ''cautions'' versus ''contraindications'', or (similarly) ''precautions'' versus ''contraindications'': these pairs of terms are respectively synonymous. Which pair is used depends on

nomenclature Nomenclature (, ) is a system of names or terms, or the rules for forming these terms in a particular field of arts or sciences. The principles of naming vary from the relatively informal conventions of everyday speech to the internationally agre ...

enforced by each organization's

style Style is a manner of doing or presenting things and may refer to: * Architectural style, the features that make a building or structure historically identifiable * Design, the process of creating something * Fashion, a prevailing mode of clothing ...

. For example, the ''

British National Formulary The ''British National Formulary'' (BNF) is a United Kingdom (UK) pharmaceutical reference book that contains a wide spectrum of information and advice on prescribing and pharmacology, along with specific facts and details about many medicines ...

'' uses the ''cautions versus contraindications'' pair, and various U.S. CDC webpages use ''precautions'' versus ''contraindications''. The logic of the latter two styles is the idea that readers must never be confused: the word ''contraindication'' in that

usage The usage of a language is the ways in which its written and spoken variations are routinely employed by its speakers; that is, it refers to "the collective habits of a language's native speakers", as opposed to idealized models of how a languag ...

''always'' is meant in its absolute

sense A sense is a biological system used by an organism for sensation, the process of gathering information about the world through the detection of stimuli. (For example, in the human body, the brain which is part of the central nervous system rec ...

, providing unmistakable

word-sense disambiguation Word-sense disambiguation (WSD) is the process of identifying which sense of a word is meant in a sentence or other segment of context. In human language processing and cognition, it is usually subconscious/automatic but can often come to cons ...

References

{{wiktionary Medical terminology

See also

References