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NIH MedlinePlus the Magazine, Trusted Health Information from the National Institutes of Health


Chronic Diseases: Asthma and You

A man, woman, and baby

What Is Asthma?

Asthma is a lung disease that inflames and narrows the airways, causing wheezing, chest tightness, shortness of breath, and coughing at night or early morning. It starts mostly in childhood but affects all age groups. Some 24.6 million Americans have asthma, seven million of them children. Asthma is a chronic—long-term—disease.


Airways are tubes that carry air into and out of your lungs. People with asthma have inflamed airways. They are swollen, very sensitive, and tend to react strongly to some inhaled substances.

When airways react, surrounding muscles tighten, airways narrow, and less air flows into the lungs. Swelling can worsen, making airways even narrower. There may be more mucus than normal, causing further narrowing.

This chain reaction can cause asthma symptoms each time airways inflame.

Sometimes, symptoms are mild and go away on their own or after treatment with medicine. Other times, they may get worse. If you have more symptoms or they get worse, you’re having an asthma attack, or flareup.

It’s important to treat symptoms when they first appear to prevent them from getting worse and causing severe attacks. Severe attacks require emergency care and can be fatal.


Asthma can’t be cured, but it can be controlled. With today’s knowledge and treatments, most asthmatics (people who have asthma) can manage the disease. They have few, if any, symptoms, live normal, active lives and sleep through the night.

For successful, ongoing treatment, manage your asthma actively. Build strong partnerships with your doctor and other healthcare providers.

Signs and Symptoms

Common signs and symptoms of asthma include:

  • Coughing at night or early in the morning, making it hard to sleep.
  • Wheezing.
  • Chest tightness, like something squeezing your chest.
  • Shortness of breath, feeling out of breath, or being unable to expel air from your lungs.

Not everyone with asthma has these symptoms. Nor does having them always mean asthma. To diagnose asthma for certain requires a lung function test, a medical history (including type and frequency of symptoms), and a physical exam.

Asthma symptoms vary in frequency and severity. Sometimes they may just annoy you. Other times they might limit your daily routine. Severe symptoms can be fatal, so it’s important to treat symptoms when you first notice them, so they don’t become severe. With proper treatment, most people can expect to have few symptoms, if any, day or night.


What Causes Asthma?

Asthma’s cause is unknown. Some genetic and environmental factors may interact to cause asthma, most often early in life, including:

  • An inherited tendency to develop allergies
  • Parents with asthma
  • Environmental exposures—to allergens, tobacco smoke, or respiratory viral infections—during pregnancy, infancy, or early childhood.

Researchers continue to explore what causes asthma.

Who Is at Risk?

Asthma affects people of all ages, but most often starts during childhood. There are more than 24.6 million Americans with asthma, seven million of them children.

Young children who frequently wheeze when they have respiratory infections and who have other risk factors—parents with asthma, eczema (an allergic skin condition), allergies—are at highest risk of asthma continuing beyond six years of age.

More boys have asthma than girls. In adults, more women than men have asthma. The role of gender and sex hormones is unclear. Most people who have asthma have allergies. Some people develop “occupational asthma” from contact with chemicals or dusts in the workplace.


Many things can set off or worsen symptoms. Triggers may include:

  • Allergens from dust mites, animal fur, cockroaches, mold, and pollen from trees, grasses, and flowers
  • Cigarette smoke, air pollution, chemicals or dust in the workplace, and sprays (such as hairspray)
  • Aspirin or other nonsteroidal anti-inflammatory drugs and some blood pressure medicines called beta blockers
  • Sulfites in foods and drinks
  • Colds and other viral upper respiratory infections
  • Physical activity, including exercise

Asthma can be harder to manage due to rhinitis, sinus infections, reflux disease, psychological stress, and sleep apnea. These need to be included as part of an overall asthma care plan.

Asthma is different for each person. Some triggers listed above may not affect you. Others that do may not be on the list. Talk with your doctor about what seems to make your asthma worse, and how you can reduce your exposure to them.


Asthma is diagnosed based on your medical and family histories, a physical exam, and test results. You may need to see an asthma specialist if you:

  • need special tests to help diagnose asthma
  • have had a life-threatening asthma attack
  • need more than one kind or higher doses of a medicine to control, or have problems controlling your asthma
  • are considering getting allergy treatments

Medical and Family Histories

Your doctor may ask about your family history of asthma and allergies, and whether, how often, and when you have asthma symptoms. Be sure to say whether your symptoms happen only during certain times and in certain places, or if they get worse at night.

Your doctor also may ask what triggers or worsens your symptoms, and about related health conditions that can interfere with asthma management, such as a rhinitis, sinus infections, reflux disease, psychological stress, and sleep apnea.

Two women walking

Asthma treatment for certain groups of people—such as children, pregnant women, or those for whom exercise brings on asthma symptoms—will need to be adjusted to meet their special needs.

Physical Exam

Your doctor will listen to your breathing and examine your chest, nose, and skin for signs of asthma or allergies, including wheezing, rhinitis, or swollen nasal passages, and allergic skin conditions (such as eczema). You can still have asthma even if you don’t exhibit these signs when you are examined.

Diagnostic Tests

Lung Function Test

Your doctor will check your lungs, including how fast you can blow air out. You may be given medicine, then tested again to see whether the results have improved. If the initial results are below normal and improve with the medicine, and if your medical history shows a pattern of asthma symptoms, you are likely to be diagnosed with asthma.

Other Tests

Other tests to diagnose asthma include:

  • Allergy testing.
  • Measuring sensitivity of airways. This test repeatedly measures lung function during physical activity or after receiving increasing doses of cold air or breathing in a special chemical.
  • Comparing your symptoms with those of conditions similar to asthma’s, such as reflux disease, vocal cord dysfunction, or sleep apnea.
  • A chest X-ray or EKG (electrocardiogram) to help find out whether a foreign object or other disease may be causing your symptoms.

Diagnosing Children

Most children develop asthma before they are five, but it can be hard to diagnose. Sometimes, asthma symptoms occur with other conditions. Also, many young children who wheeze when they get colds or respiratory infections don’t develop asthma.

A child may wheeze because he or she has small airways that become even narrower during colds or respiratory infections. The airways grow as the child grows older, so wheezing stops. A young child who has frequent wheezing with colds or respiratory infections is more likely to develop asthma if:

  • One or both parents have asthma
  • The child has signs of allergies, including the allergic skin condition eczema
  • The child wheezes even when he or she doesn’t have a cold or other infection

The most certain way to diagnose asthma is with a lung function test, medical history, and physical exam. However, it’s hard to do lung function tests in children younger than five. Doctors must rely on medical histories, signs and symptoms, and physical exams. A four to six-week trial of asthma medicines to see how well a child responds also may be used.

Treatment and Control

Since asthma can’t be cured, the goal is to:

  • Prevent chronic, troublesome coughing, shortness of breath, and other symptoms
  • Reduce the need for quick-relief medicines
  • Help maintain good lung function
  • Maintain normal activity and sleep through the night
  • Prevent attacks resulting in emergency room visits or hospital stays

Everyone, including younger children who are able, should actively manage their asthma care.

This involves:

  • Following a written asthma action plan that you develop with your doctor
  • Taking medicines correctly
  • Avoiding asthma triggers (except physical activity; you can take medication to allow full participation in physical activities
  • Recognizing and acting promptly to symptoms and signs of worsening asthma
  • Seeking medical care for asthma attacks when it is needed
  • Getting regular “asthma checkups” (about every six months if your asthma is in good control; more frequently if it is not)
  • Treating other conditions that can interfere with asthma management


Asthma is treated with long-term control and quick-relief medicines. The former help reduce airway inflammation and prevent asthma symptoms; the latter relieve asthma symptoms that flare up. The initial treatment for long-term management of asthma depends on the severity of the asthma. Long-term follow-up treatment depends on how well the asthma is controlled.

Control can vary over time and with changes in home, school, or work environments, which alter exposure to asthma triggers. Medicines may need to be increased if asthma doesn’t stay under control. If it does, they may be decreased. The goal is to maintain the best control possible with the least amount of medicine necessary.

Asthma treatment for certain groups of people—such as children, pregnant women, or those for whom exercise brings on asthma symptoms—will need to be adjusted to meet their special needs.

Fall 2011 Issue: Volume 6 Number 3 Page 5-7