The cause is unknown. Asthma is a very common disease. Asthma can be diagnosed by a history, physical examination and lung function tests. Skin tests to identify allergens are sometimes used to aid in diagnosis and management. There is no cure for asthma, but the symptoms can be controlled.
Persistent asthma occurs more than twice a week.
Rescue drugs open up the airways to improve breathing. Control medications are taken even when no symptoms are present, and are designed to decrease lung inflammation. 3rd Edition, Humana Press. A concise review on all the issues related to allergy. The Complete Guide to Diagnosis, Treatment and Daily Management .