A common cause of breathing difficulty, particularly in children, is asthma. An attack can be frightening both for the sufferer and for an observer. It usually comes on suddenly and may last for minutes, hours or even days. Symptoms include a whistling sound when breathing in and wheezing when breathing out, accompanied by a dry cough and the development of phlegm in the lungs.

The patient may feel as if he or she is suffocating. The immediate causes of the breathing problems experienced during the height of an asthma attack are spasm of muscles in the air-tubes of the lungs, narrowing of the bronchi and blockage of the airways by mucus. The reasons for why asthma occurs in the first place are less easy to identify. Allergy, changes in the weather, infection, and emotional excitement or stress would all appear to play a part, either singly or in combination. All that can be said with some degree of certainty is that when subject to these factors, the bronchi of asthmatics contract instead of relaxing .

Most asthmatics carry an inhaler around with them that artificially expands the bronchi when they have an attack. In severe cases, hospitalization is necessary so that they can receive oxygen or mechanically-aided respiration. In less severe cases, the sufferer should be encouraged to sit upright and given something to support his or her back. Something to hold on to so that the arms can assist breathing is also useful. The simplest of remedies, a hot drink, may occasionally alleviate the worst symptoms.