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asthma





Contents
  • What causes asthma?
  • Who is at risk for asthma?
  • Signs and symptoms
  • Diagnosis
  • Treatment
  • Prevention
  • Living with asthma
  • A chronic respiratory disease that affects the airways and is marked by recurrent attacks for wheezing and acute breathlessness. It is due to abnormal bronchial sensitivity which can cause the bronchi to go into spasm and is usually associated with allergy to house dust mite, pollen, fungi, furs, and other substances that can trigger an attack. Chest infection, exercise, or emotional upset may also be triggers.

    The airways are the tubes that carry air in and out of the lungs. If you have asthma, the inside walls of your airways are inflamed (swollen). The inflammation makes the airways very sensitive, and they tend to react strongly to things that you are allergic to or find irritating. When the airways react, they get narrower, and less air flows through to your lung tissue. This causes symptoms like wheezing (a whistling sound when you breathe), coughing, chest tightness, and trouble breathing, especially at night and in the early morning.

    Asthma cannot be cured, but most people with asthma can control it so that they have few and infrequent symptoms and can live active lives.

    When your asthma symptoms become worse than usual, it is called an asthma episode or attack. During an asthma attack, muscles around the airways tighten up, making the airways narrower so less air flows through. Inflammation increases, and the airways become more swollen and even narrower. Cells in the airways may also make more mucus than usual. This extra mucus also narrows the airways. These changes make it harder to breathe.

    asthma

    Asthma attacks are not all the same – some are worse than others. In a severe asthma attack, the airways can close so much that not enough oxygen gets to vital organs. This condition is a medical emergency. People can die from severe asthma attacks.

    So, if you have asthma, you should see your doctor regularly. You will need to learn what things cause your asthma symptoms and how to avoid them. Your doctor will also prescribe medicines to keep your asthma under control.

    Taking care of your asthma is an important part of your life. Controlling it means working closely with your doctor to learn what to do, staying away from things that bother your airways, taking medicines as directed by your doctor, and monitoring your asthma so that you can respond quickly to signs of an attack. By controlling your asthma every day, you can prevent serious symptoms and take part in all activities.

    If your asthma is not well controlled, you are likely to have symptoms that can make you miss school or work and keep you from doing things you enjoy. Asthma is one of the leading causes of children missing school.





    What causes asthma?

    It is not clear exactly what makes the airways of people with asthma inflamed in the first place. Your inflamed airways may be due to a combination of things. We know that if other people in your family have asthma, you are more likely to develop it. New research suggests that being exposed to things like tobacco smoke, infections, and some allergens early in your life may increase your chances of developing asthma.

    There are things in the environment that bring on your asthma symptoms and lead to asthma attacks. Some of the more common things include exercise, allergens, irritants, and viral infections. Some people have asthma only when they exercise or have a viral infection.

    The list below gives some examples of things that can bring on asthma symptoms.


    Allergens

    • Animal dander (from the skin, hair, or feathers of animals)
    • Dust mites (contained in house dust)
    • >Cockroaches
    • Pollen from trees and grass
    • Mold (indoor and outdoor)

    Irritants

    • Cigarette smoke
    • Air pollution
    • Cold air or changes in weather
    • Strong odors from painting or cooking
    • Scented products
    • Strong emotional expression (including crying or laughing hard) and stress

    Others

    • Medicines such as aspirin and beta blockers
    • Sulfites in food (dried fruit) or beverages (wine)
    • A condition called gastroesophageal reflux disease that causes heartburn and can worsen asthma symptoms, especially at night
    • Irritants or allergens that you may be exposed to at your work, such as special chemicals or dusts
    • Infections
    This is not a complete list of all the things that can bring on asthma symptoms. People can have trouble with one or more of these. It is important for you to learn which ones are problems for you. Your doctor can help you identify which things affect your asthma and ways to avoid them.


    Who is at risk for asthma?

    In the United States, about 20 million people have been diagnosed with asthma; nearly 9 million of them are children.

    Asthma is closely linked to allergies. Most, but not all, people with asthma have allergies. Children with a family history of allergy and asthma are more likely to have asthma.

    Although asthma affects people of all ages, it most often starts in childhood. More boys have asthma than girls, but in adulthood, more women have asthma than men.

    Although asthma affects people of all races, African Americans are more likely than Caucasians to be hospitalized for asthma attacks and to die from asthma.


    What are the signs and symptoms of asthma?

    Common asthma symptoms include:
    • Coughing. Coughing from asthma is often worse at night or early in the morning, making it hard to sleep.
    • Wheezing. Wheezing is a whistling or squeaky sound when you breathe.
    • Chest tightness. This can feel like something is squeezing or sitting on your chest.
    • Shortness of breath. Some people say they can't catch their breath, or they feel breathless or out of breath. You may feel like you can't get enough air in or out of your lungs.
    • Faster breathing or noisy breathing.
    Not all people have these symptoms, and symptoms may vary from one asthma attack to another. Symptoms can differ in how severe they are: Sometimes symptoms can be mildly annoying, other times they can be serious enough to make you stop what you are doing, and sometimes symptoms can be so serious that they are life threatening.

    Symptoms also differ in how often they occur. Some people with asthma have symptoms only once every few months, others have symptoms every week, and still other people have symptoms every day. With proper treatment, however, most people with asthma can expect to have few or no symptoms.


    How is asthma diagnosed?

    Some things your doctor will ask about include:
    • Periods of coughing, wheezing, shortness of breath, or chest tightness that come on suddenly, occur often, or seem to happen during certain times of the year or season
    • Colds that seem to "go to the chest" or take more than 10 days to get over
    • Medicines you may have used to help your breathing
    • Your family history of asthma and allergies
    • Things that seem to cause your symptoms or make them worse
    Your doctor will listen to your breathing and look for signs of asthma or allergies.

    Your doctor will probably use a device called a spirometer to check how your lungs are working. This test is called spirometry. The test measures how much air you can blow out of your lungs after taking a deep breath, and how fast you can do it . The results will be lower than normal if your airways are inflamed and narrowed, or if the muscles around your airways have tightened up.

    As part of the test, your doctor may give you a medicine that helps open narrowed airways to see if the medicine changes or improves your test results.

    Spirometry is also used to check your asthma over time to see how you are doing.

    Spirometry usually cannot be used in children younger than 5 years. If your child is younger than 5 years, the doctor may decide to try medicine for a while to see if the child's symptoms get better.

    If your spirometry results are normal but you have asthma symptoms, your doctor will probably want you to have other tests to see what else could be causing your symptoms.

    These include:
    • Allergy testing to find out if and what allergens affect you.
    • A test in which you use a peak flow meter every day for 1-2 weeks to check your breathing. A peak flow meter is a hand-held device that helps you monitor how well you are breathing.
    • A test to see how your airways react to exercise.
    • Tests to see if you have gastroesophageal reflux disease.
    • A test to see if you have sinus disease.
    Other tests, such as a chest X-ray or an electrocardiogram, may be needed to find out if a foreign object or other lung diseases or heart disease could be causing your symptoms. A correct diagnosis is important because asthma is treated differently from other diseases with similar symptoms.

    Depending on the results of your physical exam, medical history, and lung function tests, your doctor can determine how severe your asthma is. This is important because the severity of your asthma will determine how your asthma should be treated. One way for doctors to classify asthma severity is by considering how often you have symptoms when you are not taking any medicine or when your asthma is not well controlled.

    Based on symptoms, the four levels of asthma severity are:
    • Mild intermittent (comes and goes) – you have episodes of asthma symptoms twice a week or less, and you are bothered by symptoms at night twice a month or less; between episodes, however, you have no symptoms and your lung function is normal.


    • Mild persistent asthma – you have asthma symptoms more than twice a week, but no more than once in a single day. You are bothered by symptoms at night more than twice a month. You may have asthma attacks that affect your activity.


    • Moderate persistent asthma – you have asthma symptoms every day, and you are bothered by nighttime symptoms more than once a week. Asthma attacks may affect your activity.


    • Severe persistent asthma – you have symptoms throughout the day on most days, and you are bothered by nighttime symptoms often. In severe asthma, your physical activity is likely to be limited.
    Anyone with asthma can have a severe attack – even people who have intermittent or mild persistent asthma.


    How is asthma treated?

    Your doctor can work with you to decide about your treatment goals and what you need to do to control your asthma to achieve these goals. Asthma treatment includes:
    • Working closely with your doctor to decide what your treatment goals are and learning how to meet those goals.
    • Avoiding things that bring on your asthma symptoms or make your symptoms worse. Doing so can reduce the amount of medicine you need to control your asthma.
    • Using asthma medicines. Allergy medicine and shots may also help control asthma in some people.
    • Monitoring your asthma so that you can recognize when your symptoms are getting worse and respond quickly to prevent or stop an asthma attack.
    With proper treatment, you should ideally have these results:
    • Your asthma should be controlled.
    • You should be free of asthma symptoms.
    • You should have fewer attacks.
    • You should need to use quick-relief medicines less often.
    • You should be able to do normal activities without having symptoms.
    Your doctor will work with you to develop an asthma self-management plan for controlling your asthma on a daily basis and an emergency action plan for stopping asthma attacks. These plans will tell you what medicines you should take and other things you should do to keep your asthma under control.


    Medicines for asthma

    There are two main types of medicines for asthma:
    • Quick-relief medicines – taken at the first signs of asthma symptoms for immediate relief of these symptoms. You will feel the effects of these medicines within minutes.


    • Long-term control medicines – taken every day, usually over long periods of time, to prevent symptoms and asthma episodes or attacks. You will feel the full effects of these medicines after taking them for a few weeks. People with persistent asthma need long-term control medicines.

    Quick-relief medicines

    Everyone with asthma needs a quick-relief or "rescue" medicine to stop asthma symptoms before they get worse. Short-acting inhaled beta-agonists are the preferred quick-relief medicine. These medicines are bronchodilators. They act quickly to relax tightened muscles around your airways so that the airways can open up and allow more air to flow through.

    You should take your quick-relief medicine when you first begin to feel asthma symptoms, such as coughing, wheezing, chest tightness, or shortness of breath. You should carry your quick-relief inhaler with you at all times in case of an asthma attack.

    Your doctor may recommend that you take your quick-relief medicines at other times as well – for example, before exercise.


    Long-term control medicines

    The most effective, long-term control medicine for asthma is an inhaled corticosteroid because this medicine reduces the airway swelling that makes asthma attacks more likely.

    Inhaled corticosteroids (or steroids for short) are the preferred medicine for controlling mild, moderate, and severe persistent asthma. They are generally safe when taken as directed by your doctor.

    In some cases, steroid tablets or liquid are used for short periods of time to bring asthma under control. The tablet or liquid form may also be used to control severe asthma.

    Other long-term control medicines include:
    • Inhaled long-acting beta-agonists. These medicines are bronchodilators, or muscle relaxers, not anti-inflammatory drugs. They are used to help control moderate and severe asthma and to prevent nighttime symptoms. Long-acting beta-agonists are usually taken together with inhaled corticosteroid medicines.


    • Leukotriene modifiers (montelukast, zafirlukast, and zileuton), which are used either alone to treat mild persistent asthma or together with inhaled corticosteroids to treat moderate or severe asthma.


    • Cromolyn and nedocromil, which are used to treat mild persistent asthma.


    • Theophylline, which is used either alone to treat mild persistent asthma or together with inhaled corticosteroids to treat moderate persistent asthma. People who take theophylline should have their blood levels checked to be sure the dose is appropriate.

    If you stop taking long-term control medicines, your asthma will likely worsen again.

    Many people with asthma need both a short-acting bronchodilator to use when symptoms worsen and long-term daily asthma control medicines to treat the ongoing inflammation.

    Over time, your doctor may need to make changes in your asthma medicine. You may need to increase your dose, lower your dose, or try a combination of medicines. Be sure to work with your doctor to find the best treatment for your asthma. The goal is to use the least amount of medicine necessary to control your asthma.

    Most asthma medicines are inhaled. They go directly into your lungs where they are needed. There are many kinds of inhalers, and many require different techniques. It is important to know how to use your inhaler correctly.


    Use a peak flow meter

    As part of your daily asthma self-management plan, your doctor may recommend that you use a hand-held device called a peak flow meter at home to monitor how well your lungs are working.

    You use the peak flow meter by taking a deep breath in and then blowing the air out hard into the peak flow meter. The peak flow meter then gives you a peak flow number that tells you how fast you moved the air out.

    You will need to find out your "personal best" peak flow number. You do this by recording your peak flow number every day for a few weeks until your asthma is under control. The highest number you get during that time is your personal best peak flow. Then you can compare future peak flow measurements to your personal best peak flow, and that will show if your asthma is staying under control.

    Your doctor will tell you how and when to use your peak flow meter and how to use your medicines based on the results. You may be advised to use your peak flow meter each morning to keep track of how well you are breathing.

    Your peak flow meter can help warn you of a possible asthma attack even before you notice symptoms. If your peak flow meter shows that your breathing is getting worse, you should follow your emergency asthma action plan. Take your quick-relief or other medicines as your doctor directed. Then you can use the peak flow meter to see how your airways are responding to the medicine.

    Ask your doctor about how you can take care of your asthma. You should know:
    • What things tend to make your asthma worse and how to avoid them
    • Early signs to watch for that mean your asthma is starting to get worse (like a drop in your peak flow number or an increase in symptoms)
    • How and when to use your peak flow meter
    • What medicines to take, how much to take, when to take them, and how to take them correctly
    • When to call or see your doctor
    • When you should get emergency treatment

    Treating asthma in children

    Children with asthma, like adults with asthma, should see a doctor for treatment of their asthma. Treatment may include allergy testing, finding ways to limit contact with things that bring on asthma attacks, and taking medicine.

    Young children will need help from their parents and other caregivers to keep their asthma under control. Older children can learn to care for themselves and follow their asthma self-management plan with less supervision.

    Asthma medicines for children are like those adults use, but doses are smaller. Children with asthma may need both a quick-relief (or "rescue") inhaler for attacks and daily medicine to control their asthma. Children with moderate or severe asthma should learn to use a peak flow meter to help keep their asthma under control. Using a peak flow meter can be very helpful because children often have a hard time describing their symptoms.

    Parents should be alert for possible signs of asthma in children, such as coughing at night, frequent colds, wheezing, or other signs of breathing problems. If you suspect that your child has asthma or that your child's asthma is not well controlled, take your child to a doctor for an exam and testing.

    Your doctor will choose medicines for your child based on the child's symptoms and test results. If your child has asthma, you will need to go to the doctor for regular followup visits and to make sure that your child uses the medicines properly.


    Treating asthma in older adults

    Older adults may need to adjust their asthma treatment because of other diseases or conditions that they have. Some medicines (like beta blockers used for treating high blood pressure and glaucoma; and aspirin and other non-steroidal anti-inflammatory drugs) can interfere with asthma medicines or even cause asthma attacks. Be sure to tell your doctor about all medicines that you take, including over-the-counter ones.

    Using steroids may affect bone density in adults, so ask your doctor about taking calcium and vitamin D supplements and other ways to help keep your bones strong.


    Treating asthma in pregnancy

    If you are pregnant, it is very important to both you and your baby to control your asthma. Uncontrolled asthma can lower the oxygen level in your blood, which means that your baby gets less oxygen too.

    Most asthma medicines are generally safe to take during pregnancy. Doctors recommend that it is safer to take asthma medicines during pregnancy than to take the chance that you will have an attack.

    If you are pregnant or thinking about becoming pregnant, talk to your doctor about your asthma and how to have a healthy pregnancy.


    Treating exercise-induced asthma

    Regular physical activity is important for good health. If exercise brings on your asthma symptoms, talk to your doctor about the best ways to control your asthma when you are active. Some people with asthma use inhaled, quick-relief medicines before exercising to keep symptoms under control.

    If you use your asthma medicines as directed, you should be able to take part in any physical activity or sport you choose. Many Olympic athletes have asthma.


    Can asthma be prevented?

    We don't yet know how to prevent asthma, but there are some things that can lower your chances of having an asthma attack.

    To prevent asthma symptoms:
    • Learn about your asthma and how to control it.
    • Use medicines as directed by your doctor to prevent or stop attacks.
    • Avoid things that make your asthma worse as much as possible.
    • Get regular checkups from your doctor.
    • Follow your asthma self-management plan.
    Scientists do not yet know how to prevent the inflammation of the airways that leads to asthma. Scientists are exploring some theories:
    • Babies exposed to tobacco smoke are more likely to get asthma. If a woman is exposed to tobacco smoke during pregnancy, her baby may also be more likely to get asthma.
    • Obesity may be linked to asthma, as well as other health problems.

    Living with asthma

    If you have asthma, it is important to learn how to take care of yourself. Work with your doctor on a daily asthma self-management plan that you are both happy with.
    • Tell your doctor about all other medications you are taking, in case one of them affects your asthma.


    • Follow your asthma self-management plan and have regular checkups.


    • Learn to use your medication correctly. Ask your doctor to teach you how to use your inhaler. This is very important. If you do not use your inhalers correctly, less medication will get into your airways.


    • If you are having problems taking your asthma medicine, let your doctor know right away.
    You need to know what things bring on your asthma symptoms. Then do what you can to avoid or limit contact with these things.
    • If animal dander is a problem for you, keep your pet out of the house or at least out of your bedroom, or find it a new home.


    • Do not smoke or allow smoking in your home.


    • If pollen is a problem for you, stay indoors with the air conditioner on, if possible, when the pollen count is high.


    • To control dust mites, wash your sheets, blankets, pillows, and stuffed toys once a week in hot water. You can get special dust proof covers for your mattress and pillows.


    • If cold air bothers you, wear a scarf over your mouth and nose in the winter.


    • If you have symptoms when you exercise or do routine physical activities like climbing stairs, work with your doctor to find ways to be active without having asthma symptoms. Physical activity is important.


    • If you are allergic to sulfites, avoid foods (like dried fruit) or beverages (like wine) that contain them.
    Be alert for warning signs of an asthma attack.
    • Watch for symptoms (for example, coughing, wheezing, chest tightness, and difficulty breathing) and use your quick-relief medicine as directed by your doctor.


    • Use your peak flow meter as directed to monitor your asthma.
    If your asthma is not under control, there will be signs that you should not ignore. The following are some signs that your asthma is getting worse:
    • You have asthma symptoms more often than usual.
    • Your asthma symptoms are worse than they used to be.
    • Your asthma symptoms are bothering you a lot at night and making you lose sleep.
    • You are missing school or work because of your asthma.
    • Your peak flow number is low or varies a lot from day to day.
    • Your asthma medicines do not seem to be working very well anymore.
    • You have to use your short-acting quick-relief, or "rescue," inhaler more often. (Using quick-relief medicine every day or using more than one inhaler a month is too much.)
    • You have to go to the emergency room or doctor because of an asthma attack. You end up in the hospital because of your asthma.
    If your asthma seems to be getting worse, see your doctor. You may need to change your medicines or do other things to get your asthma under control.


    Helping your child live with asthma

    Children with asthma need the help of parents, other caregivers, teachers, and health care professionals to keep their asthma under control.

    You can help your child with asthma keep it under control. For example, you can:
    • Take your child to the doctor for regular checkups and treatment.
    • Make sure your child has an asthma self-management plan and that you know how to follow it.
    • Help your child learn about asthma and how to control it.
    • Help your child learn what things cause his or her asthma symptoms and how to avoid them, if possible.
    • Protect your child from tobacco smoke by not smoking and not allowing people to smoke in your home.
    • Find ways to reduce your child's exposure to allergens that bring on asthma attacks, like pollen, dust mites, cockroaches, or animal dander.
    • Make sure your child knows how to take asthma medicines correctly (if your child is old enough to use an inhaler without your help).
    • Make sure that your child uses a peak flow meter to help monitor and control asthma.
    • Encourage your child to take part in physical activity. Work together to keep his or her asthma under control. Your child can be active.
    • Talk to your child's other caregivers, teachers, or coaches about his or her asthma; give them copies of your child's asthma self-management plan.

    Related category

       • HEALTH AND DISEASE

    Source: U.S. National Heart, Lung and Blood Institute