Fremitus is a vibration transmitted through the body. In common medical usage, it usually refers to assessment of the lungs by either the vibration intensity felt on the chest wall (''tactile fremitus'') and/or heard by a stethoscope on the chest wall with certain spoken words (''vocal fremitus''), although there are several other types.

Types

Vocal fremitus

When a person speaks, the vocal cords create vibrations (''vocal fremitus'') in the

tracheobronchial The respiratory tract is the subdivision of the respiratory system involved with the process of respiration in mammals. The respiratory tract is lined with respiratory epithelium as respiratory mucosa. Air is breathed in through the nose to ...

tree and through the lungs and chest wall, where they can be felt (''tactile fremitus''). This is usually assessed with the healthcare provider placing the flat of their palms on the chest wall and then asking a patient to repeat a phrase containing low-frequency vowels such as "blue balloons" or "toys for tots" (the original diphthong used was the German word neunundneunzig but the translation to the English 'ninety-nine' was a higher-frequency diphthong and thus not as effective in eliciting fremitus). An increase in tactile fremitus indicates denser or inflamed lung tissue, which can be caused by diseases such as

pneumonia Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severi ...

. A decrease suggests air or fluid in the

pleural space The pleural cavity, pleural space, or interpleural space is the potential space between the pleurae of the pleural sac that surrounds each lung. A small amount of serous pleural fluid is maintained in the pleural cavity to enable lubrication bet ...

s or a decrease in lung tissue density, which can be caused by diseases such as

chronic obstructive pulmonary disease Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. The main symptoms include shortness of breath and a cough, which may or may not produce ...

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, co ...

Pleural fremitus

Pleural fremitus is a palpable vibration of the wall of the thorax caused by friction between the parietal and visceral pleura of the lungs. See

pleural friction rub A pleural friction rub, or simply pleural rub, is an audible medical sign present in some patients with pleurisy and other conditions affecting the chest cavity. It is noted by listening to the internal sounds of the body, usually using a stethosc ...

for the auditory analog of this sign.

Dental fremitus

Fremitus appears when teeth move. This can be assessed by feeling and looking at teeth when the mouth is opened and closed.

Periodontal fremitus

Periodontal fremitus occurs in either of the

alveolar bone The alveolar process () or alveolar bone is the thickened ridge of bone that contains the tooth sockets on the jaw bones (in humans, the maxilla and the mandible). The structures are covered by gums as part of the oral cavity. The synonymous t ...

s when an individual sustains trauma from occlusion. It is a result of

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, t ...

exhibiting at least slight mobility rubbing against the adjacent walls of their sockets, the volume of which has been expanded ever so slightly by inflammatory responses, bone resorption or both. As a test to determine the severity of

periodontal disease Periodontal disease, also known as gum disease, is a set of inflammatory conditions affecting the tissues surrounding the teeth. In its early stage, called gingivitis, the gums become swollen and red and may bleed. It is considered the main caus ...

, a patient is told to close his or her mouth into

maximum intercuspation In dentistry, maximum intercuspation refers to the occlusal position of the mandible in which the cusps of the teeth of both arches fully interpose themselves with the cusps of the teeth of the opposing arch. This position used to be referred to ...

and is asked to grind his or her teeth ever so slightly. Fingers placed in the labial vestibule against the alveolar bone can detect fremitus.

Rhonchal fremitus

Rhonchal fremitus, also known as bronchial fremitus, is a palpable vibration produced during breathing caused by partial airway obstruction. The obstruction can be due to mucus or other secretions in the airway,

bronchial hyperreactivity Bronchial hyperresponsiveness (or other combinations with airway or hyperreactivity, BH used as a general abbreviation) is a state characterised by easily triggered bronchospasm (contraction of the bronchioles or small airways). Bronchial hyperresp ...

, or tumors. See rhonchus (rhonchi) for the auditory analog of this sign.

Tactile fremitus

Tactile fremitus, known by many other names including pectoral fremitus, tactile vocal fremitus, or just vocal fremitus, is a vibration felt on the patient's chest during low frequency vocalization. Commonly, the patient is asked to repeat a phrase while the examiner feels for vibrations by placing a hand over the patient's chest or back. Phrases commonly used in English include, 'boy oh boy' and 'toy boat' ( diphthong phrases), as well as 'blue balloons' and 'Scooby-Doo'. 'Ninety-nine' is classically included, however, this is a misinterpretation of the original German report, in which "neunundneunzig" was the low-frequency diphthong of choice. Tactile fremitus is normally more intense in the right second intercostal space, as well as in the interscapular region, as these areas are closest to the bronchial trifurcation (right side) or bifurcation (left side). Tactile fremitus is pathologically increased over areas of consolidation and decreased or absent over areas of

pleural effusion A pleural effusion is accumulation of excessive fluid in the pleural space, the potential space that surrounds each lung. Under normal conditions, pleural fluid is secreted by the parietal pleural capillaries at a rate of 0.6 millilitre per k ...

pneumothorax A pneumothorax is an abnormal collection of air in the pleural space between the lung and the chest wall. Symptoms typically include sudden onset of sharp, one-sided chest pain and shortness of breath. In a minority of cases, a one-way valve i ...

(when there is air outside the lung in the chest cavity, preventing lung expansion). The reason for increased fremitus in a consolidated lung is the fact that the sound waves are transmitted with less decay in a solid or fluid medium (the consolidation) than in a gaseous medium (aerated lung). Conversely, the reason for decreased fremitus in a pleural effusion or pneumothorax (or any pathology separating the lung tissue itself from the body wall) is that this increased space diminishes or prevents entirely sound transmission. It has recently been suggested that the artifacts caused by eliciting tactile fremitus during breast

ultrasonography Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies fr ...

can be used to differentiate between benign and malignant tumors.

Tussive fremitus

Tussive fremitus is a vibration felt on the chest when the patient coughs.

Pericardial fremitus

Pericardial fremitus is a vibration felt on the chest wall due to the friction of the surfaces of the pericardium over each other. See

pericardial friction rub A pericardial friction rub, also pericardial rub, is an audible medical sign used in the diagnosis of pericarditis. Upon auscultation, this sign is an extra heart sound of to-and-fro character, typically with three components, two systolic and ...

for the auditory analog of this sign.

Hydatid fremitus

Hydatid fremitus is a vibratory sensation felt on palpating a

hydatid cyst Echinococcosis is a parasitic disease of tapeworms of the ''Echinococcus'' type. The two main types of the disease are ''cystic echinococcosis'' and ''alveolar echinococcosis''. Less common forms include ''polycystic echinococcosis'' and ''unic ...

References

External links

{{Respiratory system symptoms and signs Diagnostic pulmonology Medical terminology Medical signs