Asthma is known as a chronic inflammatory disease and affects the airways. There are a number of ways in which people can contract asthma. It can be genetic, so passed on from the parents to their offspring. It can also be due to the environment, like through smoking, due to hygiene, use of antibiotics, or because of certain chemicals.

An asthma sufferer is sensitive to specific stimuli known as allergens. If they breathe in this allergen an inflammatory response is triggered and the white blood cells release histamines causing the bronchioles to narrow, a process called bronchoconstriction. The airways are blocked further by the secretion of more mucus by the epithelial cells. This makes it harder for air to reach the lungs and the chest tightens and makes the sufferer cough and wheeze due to the mucus build up. The tidal volume is reduced which means the rate of oxygen diffusion slows down and less oxygen is carried in the blood for cellular respiration.

This effect could also be brought on by an emotional stimuli. In extreme cases, someone can have an asthma attack in which they find it very hard to breath.

The most common treatment for asthma is with an inhaler. They can contain medication which is either fast acting or for long term control.