"Most children and adults with asthma find they have times when their breathing becomes more difficult. Some people with more severe asthma may have breathing problems most of the time. The exact cause of asthma is unknown. People with asthma have inflamed (swollen) and sensitive airways that become narrow and clogged with sticky mucus in response to certain triggers. Factors such as a genes, air pollution, chlorine in swimming pools and modern hygiene standards have been suggested as possible causes, but there's not currently enough evidence to be certain whether any of these do cause asthma. The main treatments are: • avoiding asthma triggers whenever possible • short-acting reliever inhalers – inhalers used when needed to quickly relieve asthma symptoms for a short time, by relaxing the breathing tubes • preventer inhalers – inhalers used regularly every day to reduce inflammation in the breathing tubes and stop asthma symptoms occurring • combined preventer and long-acting reliever inhalers – inhalers used regularly every day which help stop asthma symptoms occurring and relax the breathing tubes for a longer period Download this free Asthma application to learn more about asthma copd"