We call them relievers and preventers and they work in different ways. Preventers help protect the airways. They make asthma symptoms less likely. Other treatments such as long lasting relievers and preventer tablets are also available. For more information, see our booklet Take Control of Asthma or our factsheet Preventer Tablets.
Relievers work almost immediately to relieve the symptoms of asthma.
That is why they are sometimes called rescue relievers. You should keep your reliever with you or close at hand at all times. You never know when you might need it. It takes around 30 minutes to work. Preventers usually come in brown, orange, red or white inhalers.