Inhalers have transformed asthma treatment. They enable children and adults with asthma to deliver medicine directly to their lungs nearly anytime and anywhere. A variety of inhalers are available to help relieve or control asthma symptoms. Two common types include metered-dose inhalers and dry powder inhalers.

Using an inhaler is just one part of your asthma treatment plan, which may also include checking your lung function with a peak flow meter, eliminating asthma triggers and exercising. But knowing what types of inhalers are available and how to use them can help you better manage your asthma and get the most from your treatment.

Inhalers are hand-held portable devices that deliver medication directly to the lungs. A variety of inhalers exist, but they basically fall into two categories:

• Metered-dose inhalers. These inhalers use a chemical propellant to push the medication out of the inhaler. The medication may be released by squeezing the canister or by direct inhalation.
• Dry powder inhalers. These inhalers don't use a chemical propellant to push the medication out of the inhaler. Instead, the medication is released by your inhaling more rapidly than you would with a traditional metered-dose inhaler.

Asthma inhalers are used to deliver a variety of asthma medications — some that assist with long-term control and others that provide quick relief of symptoms. Inhaled asthma medications include:

• Short-acting bronchodilators. These medications, including albuterol (Proventil, Ventolin) and pirbuterol (Maxair), provide immediate relief of asthma symptoms.
• Long-acting bronchodilators. These medications relieve asthma symptoms for longer periods of time. They include salmeterol (Serevent) and formoterol (Foradil).
• Corticosteroids. Used long term to prevent asthma attacks, these medications include beclomethasone dipropionate (QVAR), fluticasone (Flovent), budesonide (Pulmicort), triamcinolone acetonide (Azmacort) and flunisolide (Aerobid).
• Cromolyn or nedocromil. These nonsteroidal medications are used long term to prevent inflammation.
• Corticosteroid plus long-acting bronchodilator. This medication combines a corticosteroid and a long-acting bronchodilator (Advair).

Inhalers may come with slightly different instructions. Follow those instructions carefully and ask your doctor for a demonstration.

• Metered-dose inhalers. These inhalers include a pressurized canister with measured doses of medication inside. Squeezing the top of the canister converts the medication into a fine mist. Some metered-dose inhalers are breath actuated and don't require you to squeeze the inhaler. You place your lips on or near the inhaler's mouthpiece to inhale the mist.

  Using the type of metered-dose inhaler with a pressurized canister calls for coordinating two actions: squeezing the canister and inhaling the medication. You may find it easier to do this with a spacer — a short tube that attaches to the inhaler. The spacer acts as a holding chamber that keeps the medication from escaping into the air. Releasing the medication into the chamber gives you time to inhale more slowly. It decreases the amount of medicine that's deposited on the back of your throat and increases the amount that reaches your lungs.

• Dry powder inhalers. Dry powder inhalers require you to place your lips on the mouthpiece and inhale more rapidly than you would with a traditional metered-dose inhaler. Some people find dry powder inhalers easier to use than the conventional pressurized metered-dose inhalers because hand-lung coordination isn't required. Available types include a dry powder tube inhaler, a powder disk inhaler and a single dose dry powder disk inhaler. Spacers can't be used with dry powder inhalers.

Inhalers enable people with asthma to lead active lives without fear of an attack. Because inhalers are portable, they're convenient and can provide immediate relief. But it's important to use inhalers properly in order for the medications to be effective.

You may find it difficult to take asthma medication regularly, particularly corticosteroids or other medicines used to prevent asthma symptoms over the long term. You may not feel any immediate benefit from these medications. But if you don't take them regularly, as prescribed, you may have problems later on. For example, you may rely too heavily on inhaled bronchodilators. These fast-acting medications can relieve symptoms quickly, but they're no substitute for the long-term medications that keep your asthma under control.

In addition to taking the medications you're prescribed, it's important that you use your inhaler(s) correctly so that the medication reaches your lungs. Carefully follow the instructions. And ask a doctor, nurse or pharmacist for a demonstration. Use the inhaler in front of this person and ask for feedback. Then practice at home in front of a mirror.

If you're unable to use an inhaler, a nebulizer may be an option. Nebulizers are designed for those who can't use an inhaler, such as infants, young children and those who are seriously ill. The device works by converting medication into a mist and delivering it through a mask that you wear over your nose and mouth.