Asthma is a chronic disease that involves inflammation of the lungs. Airways swell and restrict airflow in and out of the lungs, making it hard to breathe. The word asthma comes from the Greek word for "panting." People with asthma pant and wheeze because of the restricted flow of air.

Normally, when you breathe in an irritant or are subjected to stressful activity such as exercise, your airways relax and open, allowing the lungs to get rid of irritants or take in more air. With asthma, muscles in the airways tighten, and the lining of the air passages swells.

About 20 million Americans have asthma, including 9 million children. In fact, asthma is the most common chronic childhood illness. About half of all cases develop before the age of 10, and many children with asthma also have allergies.

Asthma can either be allergic or non-allergic. In allergic asthma, an allergic reaction to an inhaled irritant -- pet dander, pollen, dust mites -- triggers an attack. The immune system gets involved, but instead of helping, it causes inflammation. This is the most common form of asthma.

Non-allergic asthma does not involve the immune system. Attacks can be triggered by stress, anxiety, cold air, smoke, or a virus. Some people experience symptoms only when they exercise, a condition known as exercise-induced asthma.

While there is no cure for asthma, it can be controlled.

Most people with asthma may go for periods of time without any symptoms, then experience an asthma attack. Some people experience chronic shortness of breath that gets worse during an attack. Asthma attacks can last minutes to days, and can become dangerous if the airflow becomes severely restricted.

Primary symptoms include:

• Shortness of breath
• Wheezing -- usually begins suddenly; may be worse at night or early in the morning; can be made worse by exposure to cold air, exercise, and heartburn; is relieved by using bronchodilators (drugs that open the airways; see Medications)
• Chest tightness
• Cough (dry or with sputum) -- in cough-variant asthma, this may be the only symptom

If you experience any of these symptoms, seek emergency treatment:

• Extreme difficulty breathing or cessation of breathing
• Bluish color to the lips and face (called cyanosis)
• Severe anxiety
• Rapid pulse
• Profuse sweating
• Decreased level of consciousness (such as drowsiness or confusion)

Asthma is most likely caused by a combination of several factors. Genes play a part; you’re more likely to develop asthma if others in your family have it. Among those who are susceptible, exposure to environmental factors such as allergens (substances that cause an allergic reaction) or infections may increase the likelihood of developing asthma.

The following factors may increase the risk of developing asthma:

• Having allergies
• Family history of asthma or allergies
• Exposure to secondhand smoke
• Having upper respiratory infections as an infant
• Living in a large city
• Gender -- among younger children, asthma develops twice as often in boys as in girls, but after puberty it may be more common in girls
• Obesity
• Gastroesophageal reflux (heartburn)

Triggers

Childhood asthma in particular can be triggered by almost all of the same things that trigger allergies, such as:

• Sensitivity to allergens such as dust, cockroach waste, pet dander, indoor and outdoor mold, pollen
• Air pollutants, such as smoke, aerosols, perfumes, diesel particles, sulfur dioxide, high ozone levels, and fumes from paint, cleaning products, and gas stoves
• Changes in the weather, especially in temperature (particularly cold) and humidity

Other triggers include:

• Activities that affect breathing (exercising, laughing, crying, yelling)
• Stress and anxiety

The symptoms of asthma can mimic several other conditions, and your doctor will take a thorough history to rule out other diseases. You may also have lung function tests to measure, among other things, how much air your lungs can hold and how much air you exhale. Your doctor may use a spirometer to measure how much air you exhale and how quickly you get air out of your lungs. Other tests may include chest and sinus x-rays, blood tests, or allergy tests.

Asthma is classified as

• Mild intermittent: Having mild symptoms up to 2 days a week and 2 nights a month
• Mild persistent: Having symptoms more than 2 a week but not more than one time in a single day
• Moderate persistent: Having symptoms once a day and more than one night per week
• Severe persistent: Having symptoms throughout the day on most days and often at night.

Although there is no way you can prevent asthma, you can take several steps to reduce the number and frequency of attacks:

• Avoid allergens and irritants as much as possible. For example, to reduce exposure to dust mites, use special mattress and pillow covers that keep allergens out and remove carpets from bedrooms. Clean your house frequently.
• Exercise. Even people with exercise-induced asthma can stay active, and exercise will benefit you by strengthening your lungs and helping you maintain a proper weight. Taking precautions when it’s cold outside -- such as wearing a face mask to warm the air that you’re breathing -- can help you avoid asthma symptoms. Talk to your doctor before starting an exercise regimen.
• Pay attention to your breathing. Watch for signs of an oncoming attack, such as wheezing. Your doctor may give you a machine called a peak flow meter that can detect slight differences in your breathing before you even notice them and allow you to take medication immediately to ward off an attack.
• Treat attacks quickly. The sooner you treat an attack, the less severe it will be, and the less medication you’ll need.

If you have allergies, a process known as allergy desensitization may decrease the number of asthma attacks and their intensity, and lower the amount of medication you need. Desensitization includes regular injections of the allergen (substance causing the allergic reaction), with each shot containing a slightly higher amount. Gradually your immune system becomes used to the allergen and no longer attacks it. Talk to your doctor about whether desensitization is right for you.

Avoiding asthma attacks, reducing inflammation, and preventing lung damage are the primary goals of treatment. The more you know about your condition, the more you can work closely with your doctor to develop a treatment plan. Preventing exposure to allergens or irritants and taking medication as prescribed are important for the successful control of asthma. You may need emergency medications during an asthma attack, but monitoring your breathing taking your medications every day will help you control asthma over the long term.

Severe attacks may require hospitalization for oxygen and medications that are given intravenously (IV).

Lifestyle

• If you smoke, quit.
• Lose weight if you are overweight; excess weight may put pressure on the lungs and trigger an inflammatory response.
• Monitor your condition every day using a peak flow meter (a portable device that helps measure how your lungs are working). Keep a diary of readings to show your doctor; together, you will establish your "personal best" reading. You should call your doctor if your peak flow reading falls below 80% of your personal best and go to the hospital if it falls below 50%.
• Keep a journal that logs changes or attacks -- it may help determine triggers

Medications

Medications for asthma are prescribed for two different purposes: to stop an immediate attack, and to control inflammation and reduce lung damage over the long term.

Quick relief medications -- These drugs are called bronchodilators and help open the airways when you have an attack.

Short-acting beta-adrenergic agonists start working immediately. These drugs include:

• Albuterol (Proventil)
• Isoproterenol (Isuprel)
• Metaproterenol (Aluprent)
• Pirbuterol (Maxair)
• Terbutaline (Brethine)
• Levalbuterol (Xopenex)

Another drug that might be prescribed to help open your airway is ipratropium (Atrovent).

Sometimes, steroids are needed for an acute asthma attack. They can take longer to work (from a couple of hours to a few days) and include:

• Prednisone
• Prednisolone
• Methylprednisolone
• Hydrocortisone

Long-term control -- These drugs are usually taken every day.

Inhaled corticosteroids reduce inflammation have fewer side effects than oral corticosteroids. They include

• Beclamethasone (Qvar)
• Budesonide (Pulmicort)
• Flunisolide (Aerobid)
• Fluticasone (Flovent)
• Triamcinolone (Azmacort)

A class of drugs called leukotreine modifiers help reduce the production of inflammatory chemicals called leukotreines that cause your airways to swell. They include:

• Montelukast (Singulair)
• Zafirlukast (Accolate)

Cromolyn (Intal), Nedocromil (Tilade) -- These medications, which are inhaled, can help prevent mild to moderate attacks and are used to treat exercise-induced asthma.

Theophylline (TheoDur) -- This medication helps open airways and prevent asthma symptoms, especially at night. Too much can cause serious side effects, so your doctor will monitor levels in your blood.

Nutrition and Dietary Supplements

Although asthma cannot be cured by any nutritional supplement, people who have a chronic illness such as asthma should eat well-balanced meals that include plenty of fruits and vegetables. Some studies have shown that people with asthma tend to have low levels of certain nutrients, but there is no evidence that taking supplements has any benefit. Rather, an overall healthy diet will ensure you get the nutrients you need and help your body deal with a long-term condition such as asthma.

• Choline (3 g per day) -- Choline, a B vitamin, may help reduce the severity and frequency of asthma attacks, and allow people with asthma to use bronchodilators less often. Some evidence indicates that higher doses (3 g per day) may be most effective. More research is needed to say for sure whether choline helps.
• Magnesium -- The suggestion of taking magnesium to treat asthma comes from the fact that people who have asthma often have low levels of magnesium, and from some (but not all) studies showing that intravenous (IV) magnesium can be effective as an emergency treatment for an asthma attack. However, studies that have looked at whether taking magnesium orally was beneficial have shown mixed results. More research is needed.
• Omega-3 fatty acids -- The evidence for using omega-3 fatty acids (fish oil) to treat asthma is mixed. At least a few studies have found that fish oil supplements may improve inflammation and symptoms in children and adults with asthma. But the studies have only included a small number of people, and one study found that fish oil might make aspirin-induced asthma worse. Talk to your doctor about whether a high quality fish oil supplement makes sense for you.
• Quercetin -- Quercetin, a kind of antioxidant called a flavonoid, inhibits the production and release of histamine and other allergic/inflammatory chemicals in the body. Histamine contributes to allergy symptoms such as a runny nose, watery eyes, and hives. Because of that, quercetin has been proposed as a treatment for asthma, but no human studies have examined whether it works or not.
• Selenium -- Studies suggest that people with asthma tend to have low levels of selenium. In addition, a population-based study suggested that eating selenium-rich foods may reduce the risk of asthma. And in one small study of 24 people with asthma, those who received selenium supplements for 14 weeks had fewer symptoms than those who received placebo. However, a recent study indicated that people who took 200 mcg of selenium per day for about eight years were more likely to develop type 2 diabetes. Talk to your doctor before taking selenium supplements.
• Vitamin C (1 g per day) -- One preliminary study suggested that children with asthma experienced significantly less wheezing when the ate a diet that was rich in fruits with vitamin C. Vitamin C does have anti-inflammatory and antioxidant properties, which may help you maintain good health overall. Other studies have indicated that taking a vitamin C supplement (1 g per day) may help keep airways open, but other studies have found no benefit.
• Other -- Other supplements that may have benefit for asthma include:
  • Coenzyme Q 10 (CoQ10) -- if you have asthma, you may have low levels of this antioxidant in your blood. It is not known, however, whether taking CoQ10 supplements will make any difference in your symptoms.
  • Lycopene and beta-carotene -- preliminary data suggests that these two antioxidants, found in many fruits and vegetables, may help prevent exercise-induced asthma.
  • Vitamin B6 -- may be needed if you are taking theophylline because this medication can lower blood levels of this nutrient.
  • Potassium -- levels in the body also may be lowered if you take theophylline.

Herbs

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects and interact with other herbs, supplements, or medications. For these reasons, herbs should be taken with care, under the supervision of a health care practitioner.

• Boswellia (Boswellia serrata, 3 mg three times per day) -- Boswellia (also known as Salai guggal), an herb commonly used in Ayurvedic medicine (a traditional Indian system of health care), has shown promise in treating asthma. In one double-blind, placebo-controlled study, people who took boswellia had fewer attacks and improved lung function. Boswellia may help leukotreine modifiers work better. However, more research is needed. People who take medication to lower their cholesterol, or people who take nonsteroidal anti-inflammatory drugs (NSAIDs) should talk to their doctor before taking boswellia.
• Coleus forskohlii -- Coleus forskohlii is another herb used in Ayurvedic medicine to treat asthma. A few preliminary studies that used inhaled coleus powder seemed to relieve symptoms, but more research is needed to know for sure. People who have diabetes or thyroid conditions should not take coleus. If you take an anticoagulant (blood thinner), taking coleus may increase your risk of bleeding. Pregnant women should not take coleus.
• Tylophora (Tylophora indica, 250 mg one to three times per day) -- Tylophora has also been used historically to treat asthma. Some modern scientific studies show that it can help reduce symptoms, but the studies were not the best quality. More research is needed. Tylophora may cause serious side effects at high doses, so talk to your doctor before taking it. Do not take tylophora if you are pregnant, have diabetes, high blood pressure, or congestive heart failure.
• Pycnogenol (Pinus pinaster, 1 mg per pound of body weight, up to 200 mg) -- A 2002 review of studies on a standardized extract from French maritime pine bark, called pycnogenol, suggests that it may reduce symptoms and improve lung function in people with asthma. Do not use pycnogenol if you have diabetes or take medication for high blood pressure. Taking pycnogenol with an anticoagulant (blood thinner) -- including aspirin -- can increase your risk of bleeding; talk to your doctor first.
• Saiboku-to -- A traditional Japanese herbal mixture called Saiboku-to has helped reduce symptoms and allowed study participants to reduce doses of corticosteroids in three preliminary trials. In test tubes, Saiboku-to has shown anti-inflammatory effects. Saiboku-to contains several herbs, including Asian ginseng (Panax ginseng), Chinese skullcap (Baikal scutellaria), licorice (Glycyrrhiza glabra), and ginger (Zingiber officinale). Talk to your healthcare provider before taking Saiboku-to as the herbs it contains can interact with other herbs and medications.

Acupuncture

Some preliminary studies indicate that acupuncture may help reduce symptoms for some people with asthma, but not all studies agree. It is important to note that acupuncture should be used in addition to, not as a replacement for, conventional medicine when treating asthma.

Homeopathy

Although very few studies have examined the effectiveness of specific homeopathic therapies, professional homeopaths may consider the following remedies for the treatment of asthma based on their knowledge and experience. Before prescribing a remedy, homeopaths take into account a person's constitutional type-- your physical, emotional, and psychological makeup. An experienced homeopath assesses all of these factors when determining the most appropriate treatment for each individual.

• Arsenicum album -- for asthma that generally worsens between midnight and 2 am and is accompanied by restlessness, anxiety, chills, and thirst.
• Ipecacuanha -- for those with asthma, particularly children, who have significant tightness in the chest, a chronic cough with lots of phlegm that may lead to vomiting, and worsening of symptoms in hot, humid weather.
• Pulsatilla -- for asthma with yellow or greenish phlegm that gets worse in the evening, in warm, stuffy rooms, or after consuming rich, fatty foods; this remedy is most appropriate for adults or children who are tearful and clingy or sweet and affectionate.
• Sambucus -- for asthma that awakens a person at night with a sensation of suffocation; symptoms worsen when the person is lying down .

Mind-Body Medicine

Because stress and anxiety can make asthma worse, incorporating stress management techniques into daily life may help reduce symptoms. These techniques do not directly treat asthma, however.

• Hypnosis -- may be especially useful for children, who can readily learn the technique.
• Yoga -- in addition to general relaxation and reduction of stress, several studies of people with asthma have suggested that lung function improve with the regular practice. Any benefits in breathing appear to be slight, however.
• Journaling -- A study published in the New England Journal of Medicine documented the positive effect of daily journaling on people with asthma. Some theorize that journaling allows for the release of pent-up emotions and leads to overall stress reduction.

Warnings and Precautions

Long-term treatment with theophylline for asthma may reduce blood levels of vitamin B6.

Prognosis and Complications

People with asthma can live normal, active lives. Because asthma is a chronic illness, it requires self-care and monitoring over the long term, as well as close contact with your doctor. Most people with asthma have occasional attacks separated by symptom-free periods. Paying attention to your mood, lowering the stress in your life, and having a good emotional support system will help you take good care of yourself.

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