Dryness is one of six climatic pathogenic factors (ie. a quality in the environment or climate which can cause disease). Dryness is the predominant climatic factor in autumn. So diseases caused by dryness mostly appear in autumn. Examples of dryness symptoms include: dry mouth, throat, nose and dry or cracked skin, as well as scanty urine and retention of dry faeces.
In Chinese Medicine autumn is associated with the lungs, so dryness tends to impair the lungs when it invades the body. If it impairs the lungs, the lung-fluid will be reduced and lung function will be affected. This leads to a dry cough with scanty phlegm, or sticky sputum difficult to expectorate, and chest pain.