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The U.S. National Asthma Education and Prevention Program (NAEPP) guidelines for the diagnosis and management of asthma recommend:
Symptoms of asthma include:
The word asthma comes from an ancient Greek word meaning panting. Essentially, asthma is an inflammatory lung condition that makes it difficult to breathe properly.
When people inhale, the air travels through the following body structures:
Asthma is a chronic condition in which the airways undergo changes that are usually triggered by by allergens, other environmental factors, or by infection. Asthma is characterized by two specific responses:
These actions in the airway cause coughing, wheezing, and shortness of breath (dyspnea), the classic symptoms of asthma.
In the hyperreactive response, smooth muscles in the airways of the lungs constrict and narrow excessively in response to inhaled allergens or other irritants. This sudden contraction in the muscle walls of the bronchioles is called a bronchospasm. Bronchospasms can result from many different health conditions (allergies, bronchitis, chronic obstructive pulmonary disorder) but asthma is the most common cause.
Everyone’s airways constrict when exposed to allergens or irritants, but there are major differences in the hyperreactive response that occurs in people with asthma:
The hyperreactive stage is followed by the inflammatory response, which generally contributes to asthma in the following way:
Inflammation appears to be present in the lungs of all patients with asthma, even those with mild cases, and plays a key role in all forms of the disease.
Doctors don’t fully understand the causes of asthma. They believe the disorder is most likely caused by a combination of genetic (inherited) factors and environmental triggers (such as allergens and infections). Asthma tends to run in families. Children whose parents have asthma are more likely to develop it themselves.
Nearly half of adults with asthma have an allergy-related condition, which, in most cases developed first in childhood. (In patients who first develop asthma during adulthood, the allergic response usually does not play a strong causal role.)
In people with allergies, the immune system overreacts to exposure to allergens. Allergic asthma is triggered by inhaling certain substances (allergens) such as:
An asthma attack can also be triggered or aggravated by direct irritants to the lungs. Important irritants involved in asthma include cigarette smoke, indoor chemicals, and air pollution.
Respiratory viral and bacterial infections play a role in some cases of adult-onset asthma. In both children and adults with existing allergic asthma, an upper respiratory tract infection often worsens an attack.
About 19 million American adults have asthma.
Before puberty, asthma occurs more often in males, but after adolescence, it is more common in females. In adults, women are more likely to report severe symptoms than men.
Hormonal fluctuations or changes in hormone levels may affect the severity of asthma in women. Many women with asthma experience fluctuations in severity that are associated with their menstrual cycle. Some women first develop asthma during or shortly after pregnancy, while others first develop it around the time of menopause (perimenopause).
African-Americans have higher rates of asthma than Caucasians or other ethnic groups. They are also more likely to die of the disease. Ethnicity and genetics are, however, less likely to play a role in these differences than socioeconomic factors, such as having less access to optimal health care, and greater likelihood of living in an urban area (another asthma risk factor).
Studies report a strong association between obesity and asthma. Evidence also suggests that people who are overweight (body mass index greater than 25) have more difficulty getting their asthma under control. Weight loss in anyone who is obese and has asthma or shortness of breath helps reduce airway obstruction and improve lung function.
Patients with asthma often also have gastroesophageal reflux disease (GERD), which is associated with acid reflux. It is not entirely clear which condition causes the other or whether they are both due to common factors. Acid reflux can worsen asthma symptoms. Treating GERD may help improve asthma control in some patients.
Aspirin-induced asthma (AIA) is a condition in which asthma gets worse after taking aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs). AIA often develops after a viral infection. It is a particularly severe asthmatic condition, associated with many asthma-related hospitalizations. In about 5% of cases, aspirin is responsible for a syndrome that involves multiple attacks of asthma, sinusitis, and nasal congestion. Such patients also often have polyps (small benign growths) in the nasal passages. Patients with aspirin-induced asthma (AIA) should avoid aspirin and other NSAIDs, including ibuprofen (Advil and other brands, generic) and naproxen (Aleve, generic).
Doctors classify the severity of asthma into four groups (Intermittent, Mild Persistent, Moderate Persistent, and Severe Persistent) based on:
Persistent asthma is usually chronic, although it occasionally goes into long periods of remission. Long-term outlook generally depends on severity:
Death from asthma is a relatively uncommon event, and most asthma deaths are preventable. It is very rare for a person who is receiving proper treatment to die of asthma. However, even when it is not life threatening, asthma can be debilitating and frightening. Asthma that is not properly controlled can interfere with school and work, as well as with daily activities.
Asthma symptoms vary in severity from occasional mild bouts of breathlessness to daily wheezing that lasts even when a patient takes large doses of medication. After exposure to asthma triggers, symptoms rarely develop abruptly but progress over a period of hours or days.
The classic symptoms of an asthma attack are:
Not all patients experience the same signs or symptoms of asthma or experience them the same way.
The end of an attack is often marked by a cough that produces thick, stringy mucus. After an initial acute attack, inflammation lasts for days to weeks, even if it does not produce symptoms.
The following signs and symptoms may indicate a life-threatening situation:
Asthma often progresses very slowly, but it may sometimes develop to a fatal or near-fatal attack within a few minutes. It is very difficult to predict when an attack will become very serious. Any symptoms that suggest a serious attack should be immediately treated with a rescue bronchodilator. If symptoms persist, call for emergency help.
Exercise-induced asthma (EIA) is a limited form of asthma in which exercise triggers coughing, wheezing, or shortness of breath. This condition generally occurs in children and young adults, most often during intense exercise in cold dry air. Symptoms are generally most intense about 10 minutes after exercising and then gradually resolve.
EIA is triggered only by exercise and is distinct from ordinary allergic asthma in that it does not produce a long period of airway hyperactivity, as allergic asthma does. (However, some people have both forms of asthma.) People who have only EIA do not need long-term maintenance therapy.
Many patients experience a worsening of their asthma symptoms during the nighttime, especially during sleep. Attacks often occur between 2 - 4 a.m. Factors that increase the risk for nocturnal asthma include allergen exposure, sinus problems, GERD, chronic obstructive lung diseases, and the sleep-disordered breathing associated with obstructive sleep apnea.
Your doctor will want to know any patterns or triggers associated with your asthma symptoms. Be sure to let your doctor know:
If symptoms and a patient's history suggest asthma, the doctor will usually perform lung (pulmonary) function tests to confirm the diagnosis and determine the severity of the disease.
A standard test uses a spirometer, an instrument that measures the amount of air taken into and exhaled out from the lungs. The patient breathes into a tube that is connected into a machine. The spirometer can give several measures of airflow:
If the airways are obstructed, these measurements will fall. Depending on the results, the doctor will take the following steps:
Your doctor may recommend skin or blood allergy tests, particularly if a specific allergen is suspected. Allergy skin tests may help diagnose allergic asthma, although they are not recommended for people with year-round asthma.
Many other health conditions have symptoms similar to asthma:
Asthma is often a chronic condition but you can effectively manage it by:
Based on your age, symptoms, and asthma severity, your doctor will determine an individualized treatment plan. In general, doctors recommend a stepwise approach for treating asthma. Medications and dosages are increased when needed, and decreased when possible. Your record of peak flow meter readings can help your doctor manage your medications and make necessary adjustments.
These are the signs of well-controlled asthma:
It is important to understand the difference between coping with asthma attacks and controlling the disease over time.
Medications for asthma fall into two categories:
Unfortunately, many patients do not understand the difference between medications that provide rapid short-term relief and those that are used for long-term symptom control. Make sure your doctor explains how to avoid overusing your short-term bronchodilator medications and underusing your long-term corticosteroid medications. The overuse of bronchodilators can have serious consequences, while not properly using steroids can lead to permanent lung damage.
Most asthma drugs are taken through inhalers. The two basic inhaler devices are the metered-dose inhaler (MDI) and dry powder inhalers (DPIs). In a hospital setting, or when a patient cannot use an inhaler, a nebulizer may be used. A nebulizer is a device that administers the drug in a fine spray that the patient breathes in
Metered-Dose Inhaler. The metered-dose inhaler (MDI) is the standard device. It allows precise doses to be delivered directly to the lungs. The medicine is contained in a pressurized canister that is placed inside the plastic inhaler.
MDIs are often used with a spacer, which is a tube that is attached to the inhaler. The spacer serves as a holding chamber for the medication sprayed by the inhaler. The spacer helps improve the ease and efficiency of medication delivery. .
Dry Powder Inhalers. Dry powder inhalers (DPIs) deliver a powdered form of beta2-agonists or corticosteroids directly into the lungs. Unlike an MDI, dry powder inhalers do not contain a propellant and do not require a spacer. Some patients find that they are more difficult to manage than MDIs.
Guidelines from the National Asthma Education and Prevention Program (NAEPP) emphasize that most asthma medications are safe for pregnant women. The guidelines recommend that pregnant women with asthma have albuterol available at all times. Inhaled corticosteroids should be used for persistent asthma. Patients whose persistent asthma does not respond to standard dosages of inhaled corticosteroids may need a higher dosage or the addition of a long-acting beta-agonist to their drug regimen.
For severe asthma, oral corticosteroids may be necessary. The NAEPP notes that while it is not clear if oral corticosteroids are safe for pregnant women, uncontrolled asthma poses an even greater risk for a woman and her fetus. Pregnant women with asthma face increased risks for complications including pre-eclampsia (a condition associated with high blood pressure) and preterm delivery.
Quick-relief (rescue) medications work immediately to relax airways and quickly control acute asthma attacks. They are not useful for preventing attacks or controlling inflammation in the airways.
The standard quick-relief medication is a beta2-agonist inhaler. Beta2-agonists are bronchodilators. They relax and open constricted airways during an acute asthma attack..
Specific short-acting beta2-agonists include:
Short-acting beta2-agonists are usually administered through inhalation and are effective for 3 - 6 hours. They relieve the symptoms of acute attacks, but they do not control the underlying inflammation. They are used alone only for patients with mild and intermittent asthma. Most patients with asthma use a beta2-agonist only for rapid symptom relief during an asthma attack, and use a long-term control medication to prevent attacks and reduce airway inflammation. .
Side Effects of Beta2-Agonists. Side effects of all beta2-agonists may include:
Beta2-agonists have serious interactions with certain other drugs, such as beta-blockers. People with diabetes, heart disease, high blood pressure, hyperthyroidism, an enlarged prostate, or a history of seizures should use these drugs with caution.
Short-acting beta2-agonists become less effective when taken regularly over time, which increases the risk for overuse. Overdose can be serious and in rare cases even life threatening, particularly for patients with heart disease.
Oral corticosteroids are generally used for asthma flareups that do not respond to inhaler medications. Common oral corticosteroids include prednisone, prednisolone, methylprednisolone, and hydrocortisone.
For asthma treatment, oral corticosteroids are typically used for short “bursts” of treatment lasting 5 – 10 days. In some severe cases, they may be used as maintenance therapy.
Short-term side effects of oral corticosteroids include mood changes and irritability, fluid retention and weight gain, and high blood pressure. Oral corticosteroids can cause severe side effects if taken for long periods of time. These side effects include cataracts, glaucoma, osteoporosis, diabetes, osteoporosis, susceptibility to infections, and other serious conditions.
If you need to take oral corticosteroids for more than 5 days, your doctor will gradually taper off the dose. Abruptly stopping steroids can cause withdrawal symptoms.
Two inhaled drugs, ipratropium bromide (Atrovent) and tiotropium (Spiriva), are bronchodilators that are not approved for asthma treatment but are sometimes used for this purpose. Ipratropium is used as a rescue medication. Tiotropium is being studied for use as a long-term control medication.
Possible benefits of anticholinergics include:
Asthmanefrin is an over-the-counter (non-prescription) rescue bronchodilator that contains a form of epinephrine called racepinephrine. The medication is inhaled through an atomizer. Asthmanefrin came on the market in 2012 as a replacement for Primatene Mist. Primatene Mist was discontinued because its inhaler used chlorofurocarbon (CFC) propellant. (CFCs are banned because of environmental concerns.) Asthmanefrin does not use CFC. However, many doctors do not recommend the use of epinephrine products for asthma because the drug can raise heart rate and blood pressure, and may increase the risk for heart attack and stroke. In general, patients are much better off seeing a healthcare provider and using inhalers that are prescribed.
Long-term control (maintenance) medications are taken on a regular basis to prevent asthma attacks, control inflammation in the airways, and manage chronic symptoms.
Corticosteroids, also called glucocorticoids or steroids, are powerful anti-inflammatory drugs. Steroids are not bronchodilators (they do not relax the airways) and have little short-term effect on symptoms. Instead, they work over time to reduce inflammation and prevent permanent injury in the lungs. They can also help prevent asthma attacks from occurring.
Taking a corticosteroid drug through an inhaler provides effective local anti-inflammatory activity in the lungs with very few side effects elsewhere in the body. (By contrast, steroids taken by mouth have considerable side effects throughout the body.) Inhaled corticosteroids are recommended as the primary therapy for any patient needing long-term control medications for persistent asthma.
The most recent generation of inhaled steroids include fluticasone (Flovent), budesonide (Pulmicort), triamcinolone (Azmacort and others), flunisolide (AeroBid), mometasone furoate (Asmanex), and ciclesonide (Alvesco). These steroids are sometimes combined with a long-acting beta2-agonist in a single inhaler, such as budesonide-formoterol (Symbicort), fluticasone-salmeterol (Advair), or mometasone-formoterol (Dulera). Optimal timing of the dose is important and may vary depending on the medication.
Inhaled steroids are generally considered safe and effective and only rarely cause any of the more serious side effects associated with prolonged use of oral steroids. The following are possible side effects of inhaled steroids:
Long-acting beta2-agonists (LABAs) are bronchodilator drugs that help to open and relax the airways. Unlike the short-acting Beta2-agonists used for rescue medication, LABAs are used for long-term asthma control. They are not used for treating attack symptoms.
LABAs should never be used alone in the treatment of asthma in adults or children. They can be dangerous when used alone, because they can mask asthma symptoms, and they can increase the risk of asthma death unless paired with an inhaled steroid. LABAs should only be used in combination with another control medication, such as an inhaled corticosteroid. LABAs should be used for the shortest time possible, and should only be used by patients whose asthma is not adequately controlled by other asthma maintenance medications.
Salmeterol-fluticasone (Advair), formoterol-budesonide (Symbicort), and formoterol-mometasone (Dulera) are long-acting beta2 agonists products combined with a steroid in a single inhaler that are used for treatment of moderate-to-severe asthma. The LABA-only versions of these drugs are salmeterol (Serevent Diskus) and formoterol (Foradil Aerolizer).
Doctors are still trying to determine when long-acting beta2-agonists should be added to, or removed from, an asthma treatment plan. If your symptoms do not improve or if symptoms worsen with this type of drug, your doctor will recommend discontinuing it. Do not, however, stop taking this drug or other asthma medications without first talking with your doctor.
Leukotriene antagonists (also called anti-leukotrienes or leukotriene modifiers) are pills that block leukotrienes. Leukotrienes are powerful immune system factors that, in excess, produce damaging chemicals that can cause inflammation and spasms in the airways of people with asthma. As with other anti-inflammatory drugs, leukotrienes are used for prevention, NOT for treating acute asthma attacks.
Leukotriene antagonists include montelukast (Singulair, generic), zafirlukast (Accolate, generic) and zileuton (Zyflo). These drugs may be used as second-line treatment for asthma control and are sometimes used for preventing exercise-induced asthma.
Side Effects and Complications. Upset stomach, headache, and sore throat are the most common side effects of leukotriene antagonists. Because these drugs can raise liver enzyme levels, patients may need periodic liver tests..
Leukotriene antagonists may cause mental health disturbances and behavioral changes. Mood problems include agitation, aggression, anxiousness, dream abnormalities, hallucinations, depression, insomnia, irritability, restlessness, tremor, and suicidal thinking. Patients who take a leukotriene antagonist drug should be monitored for signs of behavioral and mood changes. Doctors should consider discontinuing the drug if patients exhibit any of these symptoms.
Omalizumab (Xolair) is FDA-approved for patients age 12 and older who have moderate-to-severe persistent asthma related to allergies. Omalizumab is a biologic drug that targets and blocks the antibody immunoglobulin E (IgE), a chemical trigger of the inflammatory events associated with an allergic asthma attack.
Omalizumab is given by injection every 2 - 4 weeks. It is used only to treat patients who have moderate-to-severe persistent asthma related to allergies whose symptoms are not controlled by inhaled corticosteroids.
Side Effects and Complications. About 1 in 1,000 patients who take omalizumab develop anaphylaxis (a life-threatening allergic reaction). Patients can develop anaphylaxis after any dose of omalizumab, even if they had no reaction to a first dose. Anaphylaxis may occur up to 24 hours after the dose is given.
Omalizumab should always be injected in a doctor's office, and health care providers should observe patients for at least 2 hours after an injection. Patients should also carry emergency self-treatment for anaphylaxis (such as an Epi-Pen) and know how to use it. With an Epi-Pen, or similar auto-injector device, patients can quickly give themselves a life-saving dose of epinephrine.
Anaphylaxis symptoms include:
The FDA is currently reviewing whether omalizumab may be associated with increased risk for heart and vascular problems (ischemic heart disease, arrhythmias, cardiomyopathy, heart failure, pulmonary hypertension, and blood clots).
Theophylline is a broncholdilator drug. It relaxes the muscles around the bronchioles and also stimulates breathing. Since the introduction of inhaled corticosteroids and long-acting beta2-agonists, theophylline is not used as often for asthma treatment. It may still be used in some circumstances, such as for treating nocturnal asthma. Theophylline is available in tablet, liquid, and injectable forms. Theophylline should not be used by people with peptic ulcers or GERD, and should be used with caution by anyone with heart disease, liver disease, high blood pressure, or seizure disorders.
Patients with asthma should get an annual flu vaccine, and they should be vaccinated against pneumococcal pneumonia.
Patients with asthma and chronic allergic rhinitis may need to take medications daily. Patients with severe seasonal allergies may need to start medications a few weeks before the pollen season, and to continue medicine until the season is over. Treatment of allergies and sinusitis can help control asthma..
Immunotherapy ("allergy shots") may help reduce asthma symptoms, and the use of asthma medications, in patients with known allergies. They may also help prevent the development of asthma in children with allergies. Immunotherapy poses some risk for severe allergic reactions, however, especially for children with poorly controlled asthma.
Researchers are studying an oral form of immunotherapy that uses a sublingual (under-the-tongue) tablet. Recent reviews indicate that sublingual therapy may be helpful for asthma in particular, and may also be beneficial for allergic rhinitis. However, many questions remain including dosage and duration of treatment. At this time, sublingual immunotherapy is not considered standard practice in the United States.
Respiratory infections, including the common cold, can interact with allergies to worsen asthma. People with asthma should try to minimize their risk for respiratory tract infections. Using alcohol-based hand rubs and washing hands are simple but effective preventive measures. Vaccinations for viral respiratory infections are also important.
Asthma and GERD often co-exist. Some patients find that treatment of GERD helps improve their asthma symptoms. GERD treatment includes:
Women who suspect that menstrual-related changes may influence asthma severity should keep a diary of their menstrual dates and times of asthma attacks. Sometimes, adjusting medications in anticipation of menstruation may help prevent attacks.
Many people with asthma turn to alternative therapies including high-dose vitamins, homeopathic remedies, probiotics, and herbal supplements. There is no evidence that any of these treatments are helpful for asthma.
However, because stress can worsen asthma symptoms and make breathing more difficult, alternative therapies that focus on relaxation and stress reduction may be helpful. These modalities include:
Asthma action plans create a written document for patients to manage asthma during stable times and to more easily identify when asthma is worsening. Important components of a home program include:
A peak flow meter is a handheld plastic device for measuring peak expiratory flow rate (PEFR). PEFR measures how fast you can expel air out of your lungs and is an indication of lung functioning. Changes in the PEFR may indicate problems with asthma control even before symptoms appear.
It is a good idea to keep a written record of your peak flow meter readings. This data can help your doctor adjust medications and recognize problems before they become serious. Patients who self-manage their asthma with peak air flow measurements and appropriate medication use have fewer hospitalizations and unplanned doctors' visits, and generally have a better quality of life than those who rely only on the occasional doctor or emergency room visit to control symptoms.
To use a peak flow meter, stand or sit upright, set the meter to zero, take a deep breath and exhale hard and fast into the meter. Write down the number that appears on the meter.
Tips for regular peak flow monitoring include:
It is important to avoid and control triggers that lead to asthma attacks.
Controlling Pets. Patients who already have pets and are not allergic to them probably have a low risk for developing allergies. If pets trigger asthma, take the following precautions:
Controlling for Dust. Spray furniture polish is very effective for reducing both dust and allergens. Air cleaners, filters for air conditioners, and vacuum cleaners with High Efficiency Particle Arresting (HEPA) filters can help remove particles and small allergens found indoors. Neither vacuuming nor the use of anti-mite carpet shampoo is, however, effective for removing mites in house dust. In fact, vacuuming stirs up both mites and cat allergens. If possible, avoid carpets and rugs.
Bedding, Curtains, and Bedroom Environment.
Reducing Humidity in the House. Living in a damp house is counterproductive. Dust mites thrive in humidity and damp houses increase the risk for mold. Humidity levels should not exceed 30 - 50%:
Gas Stoves, Kerosene, and Cooking. Electric stoves and ovens are healthier than gas ones for people with asthma. Gas ovens release nitrogen dioxide, a substance that can aggravate asthma symptoms. Even smoky cooking can worsen asthma. Kerosene (used in space heaters and lamps) may also produce allergic reactions.
Exterminating Pests (Cockroaches and Mice).
Avoiding Cigarette Smoke. Cigarette smoke can accelerate the decline in lung function related to asthma. Even exposure to secondhand smoke can double the risk of an asthma-related emergency room visit. Everyone should quit smoking and encourage others around them to quit.
Avoiding Outdoor Allergens.
Asthma is no reason to avoid exercise. Historically, about 10% of Olympic athletes have asthma. Some studies indicate that long-term exercise even helps control asthma and reduce hospitalization. Exercise can help control weight, which can help with asthma symptoms. Patients should consult their doctors before starting any exercise program, however.
People who enjoy running should probably choose an indoor track to avoid pollutants. Swimming is excellent for people with asthma. Yoga, which uses stretching, breathing, and meditation techniques, may also have particular benefits.
Hints for Reducing Exercise Induced Asthma (EIA). EIA occurs only after exercise and is more likely to happen during regular paced activities in cold, dry air. The following are some suggestions for reducing its impact:
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