Symptoms often get worse in the early morning and during the night. The severity of symptoms often varies from person to person and from one asthma flare-up to another. In very severe asthma attacks, a person can be so short of breath that he or she cannot breathe without significant help. More commonly, a person experiences a mild, persistent, dry cough and occasional wheezing . Often there are provoking factors, or triggers, that cause asthma symptoms.
Triggers differ from person to person.
Asthma is caused by an immune system response. The immune system overreacts to triggers and causes the airways to become inflamed and tight. Asthma is more common in children who were underweight at birth and those who live in polluted areas. A recent study also showed that the risk of asthma is one and a half times greater in children who were given formula than in those who were breast-fed as infants. Another study of 1,000 children over 6 years of age compared those who had attended day care before they were 6 months old with those who had not.