Chronic cough

In clinical guidelines chronic cough is defined as a cough lasting more than 8 weeks in adults and more than 4 weeks in children (some studies suggest that a chronic cough must persist upwards of three months). The prevalence of chronic cough is about 10% although the prevalence may differ depending on definition and geographic area. Chronic cough is a common symptom in several different respiratory diseases like COPD or pulmonary fibrosis but in non-smokers with a normal chest x-ray chronic cough are often associated with asthma, rhinosinusitis, and gastroesophageal reflux disease or could be idiopathic Generally, a cough, for example after an upper respiratory tract infection, lasts around one to two weeks; however, chronic cough can persist for an extended period of time, often several years. People with chronic cough often experience more than one cause present. The current theory about the cause of chronic cough, independent of associated condition, is that it is caused by a hypersensitivity in the cough sensory nerves, called cough hypersensitivity syndrome. There are a number of treatments available, depending on the associated disease but the clinical management of the patients remains a challenge. Risk factors include exposure to cigarette smoke, and exposure to pollution, especially particulates.

In Chinese medicine a dry, hacking cough is associated with heat or dryness. A weak cough is usually part of a deficiency pattern.