Coughing is often an early sign of asthma. The asthmatic cough is usually dry, hacking, barking and/or repetitive. Usually little or no phlegm is produced early in an attack. You may never wheeze but only cough. If you experience this, the cough is your main problem and is often referred to as cough-variant asthma.
You also may have a common cough that is the result of an upper respiratory infection, accompanied by a post nasal drip and irritation of the upper airway. Some children with asthma may develop a croupy cough that asthma medications do not relieve. Under these circumstances, a previously well-controlled asthmatic individual may actually begin to wheeze and develop an asthmatic attack. Persistent coughing for any reason in conjunction with asthma can further irritate the sensitive airway and cause bronchospasm. This phenomenon is associated with air moving rapidly and often explosively through the airways thus cooling the airways by enhanced evaporation of airway moisture. Inhaling cool or dry air also can cause similar symptoms.
If you have asthma, coughing initially should be considered a sign of bronchospasm and often can be stopped immediately with a bronchodilator. On the other hand, coughing may be the result of a cold, bronchitis, or pneumonia. It also may be secondary to a post nasal drip or another disease (lung tumor, tuberculosis, etc.) that may require further investigation and treatment.