Asthma inhalers are hand-held, portable devices that deliver medicine to your lungs. A variety of asthma inhalers are available to help control asthma symptoms. Finding the right one and using it correctly can help you get the medicine you need to prevent or treat asthma attacks.

To find the best inhaler for you, you need to find a balance between the correct medicine and the type of inhaler that suits your needs and your ability to use the inhaler correctly. Training from a healthcare professional is essential for learning to use the device you choose correctly.

These inhalers consist of a pressurized canister containing medicine that fits into a boot-shaped plastic mouthpiece. With most metered dose inhalers, medicine is released by pushing the canister into the boot.

Some types of metered dose inhalers release medicine automatically when you inhale. A few metered dose inhalers have built-in dose counters so that you know how many doses remain. Some newer devices use wireless technology to help you count doses by allowing you to track them with an app downloaded to your phone.

If your metered dose inhaler doesn't have a counter, you need to track the number of doses you've used to know when the inhaler is low on medicine. Or you can purchase a separate electronic dose counter to keep track.

For some people, such as for children or older adults, using a spacer or valved holding chamber with an inhaler might make it easier to inhale the full dose. A spacer holds medicine in a tube between the inhaler and your mouth after it's released. A valved holding chamber is a specialized spacer with a one-way valve to help control the flow of medicine.

Releasing the medicine into the spacer allows you to inhale more slowly. This increases the amount of medicine that reaches your lungs. Spacers and holding chambers require a prescription.

Dry powder inhalers don't use a chemical propellant to push the medicine out of the inhaler. Instead, the user releases the medicine by breathing in a deep, fast breath.

There are dry powder inhalers that hold multiple doses, and some hold up to 200 doses.

There also are dry powder inhalers that hold a single dose, which you fill with a capsule before each treatment.

Soft mist inhalers are propellant-free devices that are slightly larger than conventional metered dose inhalers. These devices release a low-velocity aerosol mist that can be slowly inhaled over a longer period of time than metered dose and dry powder inhalers. Soft mist inhalers can be used with a valved holding chamber or a face mask in children.

Some people can't use a standard metered dose inhaler or dry powder inhaler. Other types include:

• Metered dose inhaler with a face mask. Generally prescribed for infants or small children, this type uses a standard metered dose inhaler with a spacer. The face mask, which attaches to the spacer, fits over the nose and mouth to make sure the right dose of medicine reaches the lungs.
• Nebulizer. This device turns asthma medicine into a fine mist breathed in through a mouthpiece or mask worn over the nose and mouth. A nebulizer is generally prescribed for people who can't use an inhaler, such as infants, young children, people who are very ill or people who need large doses of medicine.

Work with a healthcare professional to decide which type of inhaler will work best for you. Have your health professional, pharmacist or other medical professional show you how to use it.

Using your inhaler correctly is critical in ensuring you get the correct dose of medicine to keep your asthma under control. Talk to your healthcare team if you're having trouble using your inhaler, or if it seems like you're not getting enough medicine.

Replace your inhaler if it has passed its expiration date or it shows that all the doses have been used.