About asthma

Asthma occurs when the main air passages of your lungs, the bronchial tubes, become inflamed. The muscles of the bronchial walls tighten, and cells in the lungs produce extra mucus further narrowing your airways. This can cause minor wheezing to severe difficulty in breathing. In some cases, your breathing may be so labored that an asthma attack becomes life-threatening.

Asthma is a chronic but treatable condition. You can manage your condition much like someone manages diabetes or heart disease. You and your doctor can work together to control asthma, reduce the severity and frequency of attacks and help maintain a normal, active life.

Symptoms

Asthma signs and symptoms can range from mild to severe. You may have only occasional asthma episodes with mild, short-lived symptoms such as wheezing. In between episodes you may feel normal and have no difficulty breathing. Some people with asthma have chronic coughing and wheezing punctuated by severe asthma attacks.

Most asthma attacks are preceded by warning signs. Recognizing these warning signs and treating symptoms early can help prevent attacks or keep them from becoming worse.

Warning signs and symptoms of asthma in adults may include:

  • Increased shortness of breath or wheezing
  • Disturbed sleep caused by shortness of breath, coughing or wheezing
  • Chest tightness or pain
  • Increased need to use bronchodilators medications that open up airways by relaxing the surrounding muscles
  • A fall in peak flow rates as measured by a peak flow meter, a simple and inexpensive device that allows you to monitor your own lung function

Children often have an audible whistling or wheezing sound when exhaling and frequent coughing spasms.

Causes

Asthma is probably due to a combination of environmental and genetic factors. You’re more likely to develop asthma if it runs in your family and if you’re sensitive to environmental allergens or irritants. Early, frequent infections and chronic exposure to secondhand smoke or certain allergens may increase your chances of developing asthma.

Exposure to various allergens and irritants may trigger your asthma symptoms. The following are common things that trigger asthma symptoms:

  • Allergens, such as pollen, animal dander or mold
  • Cockroaches and dust mites
  • Air pollutants and irritants
  • Smoke
  • Strong odors or scented products or chemicals
  • Respiratory infections, including the common cold
  • Physical exertion, including exercise
  • Strong emotions and stress
  • Cold air
  • Certain medications, including beta blockers, aspirin and other nonsteroidal anti-inflammatory drugs
  • Sulfites, preservatives added to some perishable foods
  • Gastroesophageal reflux disease (GERD), a condition in which stomach acids back up into your esophagus. GERD may trigger an asthma attack or make an attack worse.
  • Sinusitis

Approximately 14 million adults and 6 million children in the U.S. have asthma. In fact, asthma is the most common chronic illness of childhood and a common reason for missed school days. Asthma is more common in boys than in girls. But after puberty asthma is more common in females.

A number of factors may increase your chances of developing asthma. These include:

  • Living in a large urban area, especially the inner city, which may increase exposure to environmental pollutants
  • Exposure to secondhand smoke
  • Exposure to occupational triggers, such as chemicals used in farming and hairdressing, and in paint, steel, plastics, and electronics manufacturing
  • Having one or both parents with asthma
  • Respiratory infections in childhood
  • Low birth weight
  • Obesity
  • Gastroesophageal reflux disease (GERD)

Diagnosis

Diagnosing asthma can be difficult. Signs and symptoms can range from mild to very severe and are often similar to those of other conditions, including emphysema, early congestive heart failure or vocal cord problems.

In order to rule out these and other possible conditions, your doctor will likely use several tests to arrive at a diagnosis. In most cases you’ll be asked to give a complete medical history and have a physical exam. You may also be given lung (pulmonary) function tests to determine how much air moves in and out as you breathe.

The two most common tools to measure lung function are:

  • Spirometer. A spirometer is used by a medical professional to measure narrowing of your bronchial tubes. This device measures the volume of air you can exhale after you’ve taken a deep breath. A spirometer also shows how quickly you can get air out of your lungs.
  • Peak flow meter. A peak flow meter can be used at home to help detect subtle increases in airway obstruction before you notice symptoms. If the readings are lower than usual, it’s a sign your asthma may be about to flare up. Your doctor can give you instructions on how to deal with low readings.

Lung function tests often are done before and after taking a medication known as a bronchodilator to open your airways. If your lung function improves with use of a bronchodilator, it’s likely you have asthma.

If there is uncertainty about a diagnosis of asthma, your doctor may also recommend a methacholine bronchial challenge. If you have asthma, inhaling a known asthma trigger called methacholine will cause mild constriction of your airways, which can be measured with a lung function test. A positive methacholine test supports a diagnosis of asthma.

How asthma is classified
The results of your physical exam and diagnostic tests can help your doctor classify how severe your asthma is, which helps guide how it should be treated. The four main classifications of asthma are:

  • Mild intermittent. This is the mildest form of asthma. Generally, people with mild intermittent asthma have mild symptoms up to two days a week and up to two nights a month.
  • Mild persistent. You have mild persistent asthma if you have asthma symptoms more than twice a week, but no more than once in a single day.
  • Moderate persistent. If you have asthma symptoms once a day and more than one night a week, you may have moderate persistent asthma.
  • Severe persistent. This is the most severe form of asthma, causing symptoms throughout the day on most days and frequently at night.

Complications

Asthma accounts for millions of missed school days and workdays each year. It’s also a common reason for emergency room visits and hospitalizations. You can reduce your risk of severe attacks by making sure your asthma is well controlled and by knowing how to recognize and treat attacks before they occur.

Controlling your asthma can also help you avoid serious side effects from long-term use of some medications used to stabilize severe asthma. Using inhaled corticosteroids, which have fewer side effects than oral corticosteroids, can help you reduce the need for emergency treatment of asthma.

Treatment

There are several types of medications available for treating asthma. Most people use a combination of long-term control medications and quick relief medications. Your doctor can help you decide which option is best for you based on your age and the severity of your symptoms. In general, the main types of asthma medications are:

  • Long-term-control medications. These are used regularly to control chronic symptoms and prevent asthma attacks.
  • Quick-relief medications. You use these as needed for rapid, short-term relief of symptoms during an asthma attack.
  • Medications for allergy-induced asthma. These decrease your body’s sensitivity to a particular allergen and prevent your immune system from reacting to allergens.

Long-term control medications
These medications are usually taken every day on a long-term basis, to control persistent asthma.

  • Inhaled corticosteroids. These anti-inflammatory drugs are the most effective medications for asthma. They reduce inflammation in your airways and prevent blood vessels from leaking fluid into your airway tissues.

    Corticosteroids help decrease the frequency of your attacks and reduce the need for other medications you may use to control your symptoms. Because inhaled corticosteroids control most forms of asthma by delivering medication directly to your airways, they have a lower risk of side effects than are associated with oral corticosteroids. Inhaled corticosteroids include fluticasone (Flovent), budesonide (Pulmicort), triamcinolone (Azmacort), flunisolide (Aerobid) and beclomethasone (Qvar). Advair Diskus is a combination inhaler containing fluticasone and salmeterol.

    Side effects associated with inhaled corticosteroids can include hoarseness or loss of voice, oral yeast infections (thrush), and cough. Long-term use of inhaled corticosteroids may slightly increase the risk of skin thinning, bruising, osteoporosis, eye pressure and cataracts. In children, inhaled corticosteroids may slow growth.

    If you’re using a metered-dose-inhaler form of corticosteroid, be sure to use a spacer and rinse your mouth with water after each use. This reduces the amount of drug that can is swallowed and absorbed into your body. It also reduces side effects, such as mouth and throat irritation and oral yeast infections (thrush).

  • Long-acting beta-2 agonists (LABAs). These medications are part of a group of medications called bronchodilators, which open up constricted airways. Long-acting beta-2 agonists, such as salmeterol (Serevent Diskus) and formoterol (Foradil), last at least 12 hours. They’re used to control moderate and severe asthma and to prevent nighttime symptoms. Salmeterol or formoterol are used on a regular schedule along with inhaled corticosteroids and should not be used as the main treatment for asthma.

    On Nov. 18, 2005, the Food and Drug Administration (FDA) issued a public health advisory for three LABA medications, stating the medications may increase the risk of severe asthma episodes and possibly death if a severe asthma episode occurs. The three asthma medications included in the advisory are: Advair Diskus, Foradil Aerolizer and Serevent Diskus. If you experience asthma attacks and you’re taking one of these medications, you’ll need to talk with your doctor to determine the best course of action.

  • Leukotriene modifiers. These drugs reduce the production or block the action of leukotrienes — substances released by cells in your lungs during an asthma attack. Leukotrienes cause the lining of your airways to become inflamed, which in turn leads to wheezing, shortness of breath and mucus production. Leukotriene modifiers include montelukast (Singulair) and zafirlukast (Accolate).

    Leukotriene modifiers are used with other medications — such as inhaled corticosteroids — to help prevent asthma attacks. Although generally not as effective as inhaled corticosteroids, leukotriene modifiers are an option if you have mild asthma and want to avoid corticosteroids.

  • Cromolyn and nedocromil. Although they’re not effective for everyone, daily use of inhaled cromolyn (Intal) or nedocromil (Tilade) may help prevent attacks of mild to moderate asthma. They may also be used to help prevent asthma triggered by exercise.
  • Theophylline. You take this bronchodilator in pill form every day. It may be helpful for relieving your nighttime symptoms of asthma. But theophylline may cause side effects, such as nausea and vomiting, severe abdominal pain, diarrhea, acid reflux, confusion, fast or irregular heartbeat, and nervousness. If you’re taking theophylline, get regular blood tests to make sure you’re getting the correct dosage.

Quick-relief medications
Short-acting bronchodilators — often called “rescue” or “quick-relief” medications —stop the symptoms of an asthma attack in progress. You take these medications when you begin to have symptoms, such as coughing, wheezing, chest tightness or shortness of breath. You may also use short-acting bronchodilators to prevent an asthma attack when your peak flow meter shows that your readings are lower than normal.

  • Short-acting beta-2 agonists. These bronchodilators begin working within minutes and last four to six hours. But they can’t keep symptoms from coming back. The most commonly used short-acting bronchodilator for asthma is albuterol.
  • Ipratropium (Atrovent). Your doctor might prescribe this anticholinergic for the immediate relief of your asthma symptoms.
  • Oral and intravenous corticosteroids for asthma attacks. These corticosteroids — including prednisone, methylprednisolone, hydrocortisone and others — may be taken to treat acute asthma attacks or very severe asthma. They may take a few hours or a few days to be fully effective. Long-term use of these medications can cause serious side effects, including cataracts, loss of bone mineral (osteoporosis), muscle weakness, decreased resistance to infection, high blood pressure and thinning of the skin. Asthma attacks can be life-threatening and should be managed by a doctor.

Medications for asthma triggered by allergies
Other medications focus on treating allergy triggers for asthma and include:

  • Immunotherapy. Allergy-desensitization shots (immunotherapy) may help if you have allergic asthma that can’t be easily controlled by avoiding triggers. You’ll begin with skin tests to determine which allergens trigger your asthma symptoms, followed by a series of therapeutic injections containing small doses of those allergens. You generally receive injections once a week for a few months, then once a month for a period of three to five years. Over time, you should lose your sensitivity to the allergens. Immunotherapy isn’t for everyone, though. You’re most likely to benefit if it’s clear you have allergic asthma. In addition, immunotherapy carries the risk of an allergic reaction to the shot. Life-threatening reactions are rare but possible.
  • Anti-IgE monoclonal antibodies. If you have allergies, your immune system produces allergy-causing IgE antibodies to attack substances that generally cause no harm, such as pollen, dust mites and pet dander. If you have allergic asthma that’s difficult to control, omalizumab (Xolair) may reduce the number of asthma attacks you experience by blocking the action of these antibodies. That way your immune system isn’t prompted to react and cause the inflammation that makes breathing difficult.

    Xolair is used in children over 12 years old and adults with moderate to severe asthma caused by an allergy, if all other treatments have failed.

    Xolair is delivered by injection every two to four weeks. Risks include the possibility of a severe reaction within two hours of receiving the shot, blood-clotting problems, and a possible link to cancer. That link is currently being studied. Also, if you’re pregnant or breast-feeding, tell your doctor beforehand.

    Treatment by severity for better control
    Treatment based on asthma severity can help you control your asthma. According to guidelines from the American Academy of Allergy, Asthma & Immunology and the American College of Allergy, Asthma & Immunology, asthma therapy should be flexible and based on changes in symptoms, which should be assessed thoroughly each time you see your doctor. Then, treatment can be adjusted accordingly.

    For example, if your asthma is well controlled, your doctor may prescribe less medicine. If your asthma is not well controlled or getting worse, your doctor may increase your medication and recommend more frequent visits.

Prevention

The best way to prevent asthma attacks is to identify and avoid indoor and outdoor allergens and irritants. That’s easier said than done because thousands of outdoor allergens and irritants — ranging from pollen and mold to cold air and air pollution — can trigger your attacks. A number of indoor allergens, including dust mites, cockroaches, pet dander and mold, can do the same. A common asthma irritant is tobacco smoke.

Even if you reduce indoor and outdoor allergens and irritants, managing asthma can be challenging. It often takes ongoing communication and teamwork with your doctor. But by working together, you and your doctor can design a step-by-step plan for living with your condition. In addition to knowing and avoiding your triggers, develop an action plan, monitor your breathing and treat attacks early.

  • Develop an action plan. With your doctor and health care team, write a detailed plan for taking maintenance medications and managing an acute attack. Then be sure to follow your plan. Asthma is an ongoing condition that needs regular monitoring and treatment. Taking control of your treatment can make you feel more in control of your life in general.
  • Monitor your breathing. You may learn to recognize warning signs of an impending attack, such as slight coughing, wheezing or shortness of breath. But because your lung function may decrease before you notice any signs or symptoms, regularly measure your peak airflow with a home peak flow meter.
  • Treat attacks early. If you act quickly, you’re less likely to have a severe attack. You also won’t need as much medication to control your symptoms. When your peak flow measurements decrease and alert you to an impending attack, take your medication as instructed and immediately stop any activity that may have triggered the attack. If your symptoms don’t improve, get medical help as directed in your action plan.

Self-care

Although many people with asthma rely on medications to relieve symptoms and control inflammation, you can do several things on your own to maintain overall health and lessen the possibility of attacks:

  • Exercise. You don’t have to be sedentary if you have asthma. Regular exercise can strengthen your heart and lungs so that they don’t have to work so hard. Aim for 30 minutes of exercise on most days. If you’ve been inactive, start slowly and try to gradually increase your activity over time. Keep in mind that exercising in cold temperatures may trigger symptoms. If you do exercise in cold temperatures, wear a face mask to warm the air you breathe. And don’t exercise in temperatures below zero. Activities such as golf, walking and swimming are less likely to trigger attacks, but be sure to discuss any exercise program with your doctor.
  • Use your air conditioner. Air conditioning helps reduce the amount of airborne pollen from trees, grasses and weeds that finds its way indoors. Air conditioning also lowers indoor humidity and can reduce your exposure to dust mites. If you don’t have air conditioning, try to keep your windows closed during pollen season.
  • Decontaminate your decor. Minimize dust that may aggravate nighttime symptoms by replacing certain items in your bedroom. For example, encase pillows, mattresses and box springs in dust-proof covers. Remove carpeting and install hardwood or linoleum flooring. Use washable curtains and blinds.
  • Maintain optimal humidity. Keep humidity low in your home and office. If you live in a damp climate, talk to your doctor about using a dehumidifier.
  • Keep indoor air clean. Have a utility company check your air conditioner and furnace once a year. Change the filters in your furnace and air conditioner according to the manufacturer’s instructions. Also consider installing a small-particle filter in your ventilation system. If you use a humidifier, change the water daily.
  • Reduce pet dander. If you’re allergic to dander, avoid pets with fur or feathers. Having pets regularly bathed or groomed also may reduce the amount of dander in your surroundings.
  • Clean regularly. Clean your home at least once a week. Because cleaning stirs up dust, however, wear a mask or, if you can, have someone else clean.
  • Limit use of contact lenses. Try substituting eyeglasses for your contact lenses when the pollen count is high. Pollen grains can become trapped under the lenses.
  • Control heartburn and gastroesophageal reflux disease (GERD). It’s possible that the acid reflux that causes heartburn may damage lung airways and worsen asthma symptoms. If you have frequent or constant heartburn, talk to your doctor about treatment options.

Asthma can be challenging and stressful. You may sometimes become frustrated, angry or depressed because you need to cut back on your usual activities, to avoid environmental triggers. You may also feel hampered or embarrassed by the symptoms of the disease and by complicated management routines. Children in particular may be reluctant to use a metered dose inhaler in front of their peers.

But asthma doesn’t have to be a limiting condition. The best way to overcome anxiety and a feeling of helplessness is to understand your condition and take control of your treatment. Here are some suggestions that may help:

  • Identify the things that trigger your symptoms. This can be one of the most important ways to take control of your life. Also take peak flow measurements regularly and follow your action plan for using medications and managing attacks.
  • Pace yourself. Take breaks between tasks and avoid activities that make your symptoms worse.
  • Make a daily to-do list. This may help you avoid feeling overwhelmed. Reward yourself for accomplishing simple goals.
  • Talk to others with your condition. Chat rooms and message boards on the Internet or support groups in your area can connect you with people facing similar challenges and let you know you’re not alone.

If you have a child with asthma, be encouraging and supportive. Focus attention on the things your child can do, not on the things he or she can’t do. Involve teachers, school nurses, coaches, friends and relatives in helping your child manage an asthma condition.