An inhaler is an aerosol device that is used to deliver medication to the lungs. By converting medicine into a breathable mist or small granules, an inhaler allows an individual to draw medication deep into the lungs, where it is most effective. This technique is effective in the treatment of asthma, chronic obstructive pulmonary disease (COPD) and other respiratory problems.

Inhalers come in two main types:

• Metered-dose inhalers. Use a small canister of compressed air to deliver a specific dose of medication as a fine mist that is easily inhaled. 
  
  
• Dry powder inhalers. Rely on a sharp inhalation from the user to deliver small granules of medication in measured doses.

Learning to use a metered-dose inhaler properly may be difficult. Some dry powder inhalers require a powerful force when inhaling that people with lung problems may not be capable of providing. A physician can determine the best type of inhaler for a specific patient.

People who use inhalers regularly must keep careful track of how much medication they have used. It is often not obvious how much medication remains in the device, especially with metered-dose inhalers. Inhalers should be washed every day. Physicians recommend that people who use an inhaler carry it with them wherever they go, if they use it for rescue medication.

Some infants, young children and elderly people find it difficult to use inhalers. For these patients, a physician may recommend use of a nebulizer – a device that uses pressurized air to deliver liquid medication in a mist form through a mask that fits over the nose and mouth. This delivery method generally makes it easier for the patient to inhale the medication. However, nebulizers are not as commonly used as inhalers because they are inconvenient (due to their dependence on an electrical outlet). They are also much more time consuming to use. Nebulizers take around 15 minutes to use, whereas inhalers take only a matter of seconds.