Asthma is a common disease in the UK, affecting more than 3 million people. It can occur in people of any age, but is most likely to develop in children by the age of 5 and in adults during their 30s. People over 65 are also prone to the disease. Asthma is an allergic condition that is often inherited by children from their parents. This type of asthma is often related to eczema and hay fever, with 50% of adults and 80% of children who have other allergies commonly developing asthma. Symptoms of asthma in a person can increase or decrease in severity through life. Approximately 1 in 3 children who suffer from asthma will have no symptoms by the time they reach adulthood.
Asthma affects the airways and disrupts the transport of air in and out of the lungs. Asthma sufferers have sensitive airways which become inflamed and narrowed under certain conditions. The inflammation is caused by the body's immune system, in order to counteract the irritant. When inflammation occurs it becomes difficult for oxygen to reach the lungs. Consequently asthmatics may experience difficulty with breathing.
Numerous factors can be responsible for triggering an asthma attack. Asthmatics are usually allergic to more than one trigger and their asthma symptoms may vary from wheeziness, to shortness of breath, chest tightening or the over production of mucus.
Both indoor and outdoor air pollution, natural and man-made, can trigger asthma attacks. Common indoor pollutant triggers include the dustmite, mould and cigarette smoke. As much as 85% of children that experience asthmatic symptoms are allergic to dustmite. Cigarette smoke is damaging to everyone's airways, but can be particularly bad for people with asthma. Smoke causes the airways to narrow, making it more difficult to breathe.
Outdoors, natural plant, grass and tree pollen can act as triggers in some asthmatics. Man-made pollution may also be detrimental to asthmatics. Although it has not been proven that a link exists between air pollution and asthma, certain pollutants, including sulphur dioxide, nitrogen dioxide and ozone are known to restrict the airways and make it more difficult for asthma sufferers to breathe. Fine particulate matter is also suspected to be a lung irritant.
Although there is no cure for asthma at present, inhalers can be used to reduce the severity of the symptoms. Preventer inhalers may be used to build up a long-term resistance to asthma triggers, whilst reliever inhalers are used as an instantaneous means of relieving asthmatic symptoms, by relaxing the muscles controlling the airways.