Some physicians believe that a cough should not be considered to be chronic until it persists for eight weeks. In infants and children asthma is a major cause of chronic coughing. Other major causes of coughing in children at different ages include physical abnormalities in infants under 18 months, sinusitis in children 18 months to six years, and psychologic causes in older children and adolescents. A simple lung examination and medical history can often quickly determine a diagnosis. For more complicated or uncertain cases, other tests may be required, including lung function studies and x-rays.
Some experts suggest that persistent cough first be treated with antihistamines and decongestants.
If coughing doesn't resolve, asthma therapies should be added. If coughing still persists the patient should be treated for gastroesophageal reflux disorder. If such treatments fail, then more invasive tests are required. Chronic bronchitis also causes shortness of breath and is often accompanied by infection, mucus production, and coughing, but it is a long-term and irreversible condition. A diagnosis of chronic bronchitis is suggested when a patient experiences coughing with sputum on most days for at least three months of a year, for a minimum of two years.