Definition
Coughing is one of the most common symptoms, both in children and adults, and consequently a regular reason to see a doctor. Most often, coughing is a symptom of a respiratory disease (throat, pharynx, nose, windpipe) or of the lungs. As a rule, a cough is a sign of a harmless, mostly viral infection, but serious or dangerous illnesses can also manifest themselves through coughing.
For this it is important to pay attention to certain warning signs, such as sputum (for example, mucus or blood), certain triggers (especially in allergies and asthma) and the type of cough or cough that has existed for a long time. It is suspicious if the cough persists for more than three weeks. Other symptoms, such as fever, can also indicate a dangerous course and should be followed by a more detailed medical examination.
Causes
Coughing is caused by irritation of the nose, sinuses, upper or lower respiratory tract. There, specific receptors are found that react to certain stimuli and thus trigger coughing. Possible causes can be: cold air, inhaled particles (for example smoke or dust), increased mucus, citric acid, as well as other foreign and some endogenous substances, such as inflammatory substances (for example bradykinin, tachykinin and prostaglandin E2), which the body releases during inflammatory reactions, i.e. among other things during infections.
Via the tenth cranial nerve (nervus vagus), the stimulus is transmitted from the receptor to the brain, where the cough is initiated. This primarily happens in the cough center of the brain stem and is considered a reflex; coughing is therefore not an arbitrarily controllable event. The aim of coughing is to cleanse the respiratory tract when the other mechanisms that are active at any time fail.
Normally, movement of the so-called ciliated epithelium, which lines the entire respiratory tract, is sufficient to remove mucus and foreign bodies. Mucus is transported towards the oral cavity by microscopic hairs that beat rhythmically in the same direction. This effect is not sufficient in the case of very viscous mucus, as can occur in muscoviscidosis, or if there is an increase in mucus. The mucus must be coughed up.
All articles in this series:
