Health Library Explorer
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A-Z Listings Contact Us
Adult Health Library
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Topic IndexLibrary Index
Click a letter to see a list of conditions beginning with that letter.
Click 'Topic Index' to return to the index for the current topic.
Click 'Library Index' to return to the listing of all topics.


What is asthma?

Asthma is a long-term disease of the airways of the lung. The airways become sensitive to triggers (allergens and irritants). With exposure to triggers, the following changes occur:

  • The lining of the airways becomes swollen and inflamed.
  • The muscles that surround the airways tighten.
  • More mucus is produced, leading to mucus plugs.

All of these factors cause the airways to narrow. This makes it hard for air to go in and out of the lungs.

What causes asthma?

The exact cause of asthma is unknown. It is believed to be partially inherited. The environment, infections, and chemicals released by the body are also involved.

Exercise causes symptoms in many people with asthma. Symptoms can occur during, or shortly after, exercise. In some people, stress or strong emotions can cause asthma symptoms.

All of the following may be asthma triggers:



Respiratory problem

  • Pollens
  • Grasses, trees
    • Mold
    • Pets
  • Dust
  • Cockroaches
  • Nasal allergies
  • Sinus infections
  • The flu



  • Strong odors perfumes, household cleaners, cooking fumes, paints, and varnishes
  • Chemicals (gases, fumes)
  • Air pollution
  • Changing weather conditions (temperature, barometric pressure, humidity, and strong winds)
  • Smoke (tobacco-inhaled or secondhand)
  • Aspirin
  • NSAIDs (nonsteroidal anti-inflammatory drugs) such as ibuprofen, indomethacin, naproxen

Other conditions

  • GERD (gastroesophageal reflux)
  • Sleep apnea
  • Overweight
  • Depression


  • Exercise, especially in cold weather
  • Strong emotions that go along with laughing or crying

Who is at risk for asthma?

It is most common in the following people:

  • Children and teens ages 5 to17
  • Those living in cities

Other factors include the following:

  • Personal or family history of asthma or allergies
  • Exposure to secondhand tobacco smoke
  • Children with a family history of asthma
  • Children who have allergies
  • Children who have exposure to secondhand and tobacco smoke

What are the symptoms of asthma?

The symptoms of asthma include:

  • Trouble breathing or shortness of breath
  • Tightness in the chest
  • Wheezing or a whistling sound when breathing
  • Coughing
  • Breathing becomes harder and may hurt
  • Talking and sleeping may be difficult with severe symptoms

How is asthma diagnosed?

To diagnose asthma and rule out other lung disorders, health care providers rely on your medical history, physical exam, and other tests. An important test for the diagnosis and monitoring of asthma is spirometry.

A spirometer is a device that is used to determine how well the lungs are working. It measures the amount and speed of air exhaled.

Other tests may also be done to check for conditions such as allergies.

How is asthma treated?

Your health care provider will figure out the best treatment based on:

  • How old you are
  • Your overall health and medical history
  • How sick you are
  • How well you can handle specific medicines, procedures, or therapies
  • How long the condition is expected to last
  • Your opinion or preference

There is no cure for asthma. It can usually be controlled by avoiding triggers and taking medicines as prescribed by your health care provider.

Monitoring symptoms, and knowing what to do if symptoms get worse, is also a vital part of asthma care. Experts recommend making an Asthma Action Plan with your doctor.

Medicines for asthma

The two types of asthma medicines are long-term control and short-term or quick-relief medicines. Long-term control medicines are usually taken every day to control asthma symptom. Quick-relief medicines calm asthma symptoms fast, but only last for a short time. People with asthma may take either long-term or quick-relief medicines, or both.

The National Heart, Lung, and Blood Institute recommends providers regularly assess and adjust medicines as needed.

Long-term control medicines

When you first start taking long-term control medicines, it may take a few weeks for the medicines to work. It is very important to take these medicines every day. Long-term asthma control medicines include:

  • Anti-inflammatory drugs, including inhaled corticosteroids and nebulizer cromolyn and nedocromil. These medicines reduce or prevent swelling in the airways.
  • Bronchodilators, including inhaled long-acting beta2-agonists and sustained-release theophylline or sustained-release beta2-agonist tablets. These medicines relax muscles around the airways. (Inhaled long-acting beta2-agonists should never be used for long-term asthma control unless they're used with inhaled corticosteroids.)
  • Leukotriene modifiers. These medicines block the action of chemicals called leukotrienes, which cause inflammation and narrowing of the airways. 
  • Anti-IgE (omalizumab). This medicine reduces allergic reactions. It is given twice monthly by injection.

Quick-relief medicines

Quick-relief medicines quickly relax the muscles around the airways. The relief only last about 2 to 3 hours. Only control medicines give long-term control and help prevent the recurrence of symptoms.

Quick-relief medicines may include:

  • Inhaled short-acting-beta2-agonists. Short-acting beta2-agonists help relax muscles around the airways.
  • Inhaled anticholinergics. These are medicines that block a chemical called acetylcholine. Acetylcholine contracts the muscles and increases production of mucus in the airways.

Inhalation devices for asthma

Inhaled medicines go directly to the lungs. There are fewer side effects than medicines taken by mouth. Inhaled may be anti-inflammatory or bronchodilating or both. The devices are:

  • Metered-dose inhalers (MDI). This is the most common type of inhaler. It uses a chemical to push the medicine out of the inhaler.  MDIs are held in front of or inserted into the mouth as the medicine is released in puffs. Follow the instructions on the use and cleaning of the inhaler. Health care providers, nurses, respiratory therapists, and pharmacists can answer any questions. 
  • Nebulizers. A nebulizer is a device that sprays a fine mist of medicine. This is done through a mask, using oxygen or air under pressure, or an ultrasonic machine. A mouthpiece or mask is connected to a machine via plastic tubing to deliver medicine. There are different kinds of nebulizers. Some are smaller and can easily travel. Again, knowing how to use and clean a nebulizer is important. Health care professionals can help.
  • Dry powder or rotary inhalers. These inhalers deliver powered medicine as a person breaths. As with any medical device, follow all instructions.


Living with asthma

Avoiding triggers is key in the management of asthma. Triggers may be allergens, irritants, other medical conditions, exercise, medicines, and strong emotions. The following can help you limit your exposure:


  • Dust. Dust is the most common year-round allergen. The allergy is actually caused by tiny dust mites. Dust mites are found in mattresses, carpets, and upholstered furniture, like sofas and chairs. They live best in warm, humid conditions. The best way to prevent allergy symptoms caused by dust mites is to limit your exposure. Pay special attention to the bedroom where you spend a lot of your time.
  • Pollens. If you are allergic to pollen, during pollen season keep all car and house windows closed and use the air conditioning. If you are outdoors, shower, wash your hair, and change your clothes when you go inside.
  • Pets. Pets that have fur or feathers cause allergies for many people. Some people with pets are not able to keep them because of their allergies. If you do have pets, try to avoid touching them. If you do pet or handle them, wash your hands afterward. Be sure to keep pets off your bed and out of your bedroom. And, have someone brush and bathe your pet regularly.
  • Mold and mildew. These can trigger asthma. Outside, avoid damp, shady areas. Use exhaust fans when cooking or bathing. Keep indoor humidity to less than 50%.


Even though exercise is a common asthma trigger, you should not limit your participation in sports or exercise, unless directed by a health care provider. Exercise is good for your health and lungs. Activities such as swimming, golf, and karate are good choices for persons with asthma. Always warm-up before exercise and cool down at the end of exercise. Ask your doctor about using your quick-reliever medicine before starting exercise.


Avoid smoke or use wood stoves or kerosene heaters. Also avoid strong perfumes, cleaning products, fresh paint, and other things with strong odors.


Some medicines can worsen asthma symptoms. These medicines include aspirin, NSAIDs (nonsteroidal anti-inflammatory drugs), and beta-blockers used to treat heart disease and high blood pressure. Talk with your health care provider about your asthma history and use of these medicines.

Other medical conditions

Respiratory infections, such as colds and the flu, gastroesophageal reflux (GERD or heartburn), overweight, sleep apnea, depression, and other problems can make it more difficult to control asthma. Work with your doctor to treat any of these problems.

Strong emotions

Emotions that go with laughing and crying can trigger asthma symptoms. There are ways to learn how to better manage your emotions.

Key points

  • Asthma is a long-term disease of the airways.
  • Triggers irritate sensitive airways making it hard to breathe.
  • Avoiding triggers is an important part of treatment.
  • Long-term medicines control symptoms and are taken every day.
  • Rescue medicines provide relief from symptoms quickly, but the relief is only short-term.

Next steps

Tips to help you get the most from a visit to your health care provider:
  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.
Online Medical Reviewer: Akin, Louise, RN
Online Medical Reviewer: Holloway, Beth, RN, M.Ed.
Date Last Reviewed: 5/22/2014
© 2000-2015 The StayWell Company, LLC. 780 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
Powered by StayWell
About Us| Disclaimer