An inhaler (also known as a puffer, pump or allergy spray) is a medical device used for delivering medicines into the lungs through the work of a person's breathing. This allows medicines to be delivered to and absorbed in the lungs, which provides the ability for targeted medical treatment to this specific region of the body, as well as a reduction in the side effects of oral medications. There are a wide variety of inhalers, and they are commonly used to treat numerous medical conditions with asthma and chronic obstructive pulmonary disease (COPD) being among the most notable.

Some of the common types of inhalers include metered-dose inhalers, dry powder inhalers, soft mist inhalers, and nebulizers. Each device has advantages and disadvantages and can be selected based on individually specific patient needs, as well as age, pathological conditions, coordination, and lung function. Proper education on inhaler use is important to ensure that inhaled medication creates its proper effects in the lungs.