What is asthma?
Asthma is a chronic, inflammatory disease of the lungs in which the airways become sensitive to allergens (any substance that triggers an allergic reaction) and irritants (irritating things in the air). Several things happen to the airways when a person is exposed to certain triggers:
The lining of the airways becomes swollen and inflamed.
The muscles that surround the airways tighten.
The production of mucus is increased, leading to mucus plugs.
All of these factors will cause the airways to narrow, thus making it difficult for air to go in and out of your lungs, causing the symptoms of asthma.
What are the symptoms of asthma?
Asthma may resemble other respiratory problems, such as emphysema, bronchitis, and lower respiratory infections. It is often underdiagnosed and many people with the disease do not know they have it. Sometimes, the only symptom is a chronic cough, especially at night, or coughing or wheezing that occurs only with exercise. Some people think they have recurrent bronchitis, since respiratory infections usually settle in the chest in a person predisposed to asthma.
What causes asthma?
The exact cause of asthma is not completely known. It is believed to be partially inherited, but it also involves many other environmental, infectious, and chemical factors. After a person is exposed to a certain trigger, the body releases histamine and other agents that can cause inflammation in the airways. The body also releases other factors that can cause the muscles of the airways to tighten, or become smaller. There is also an increase in mucus production that may clog the airways.
Some persons have exercise-induced asthma, which is caused by varying degrees of exercise. Symptoms can occur during, or shortly after, exercise. In some people, stress or strong emotions can trigger an asthma attack. Each person has different triggers that cause the asthma to worsen. You should discuss this with your doctor.
The changes that occur in asthma are believed to happen in two phases:
An immediate response to the trigger leads to swelling and narrowing of the airways. This makes it initially difficult to breathe.
A later response, which can happen four to eight hours after the initial exposure to the allergen, leads to further inflammation of the airways and obstruction of airflow.
What are the risk factors for an asthma attack?
Although anyone may have an asthma attack, it most commonly occurs in the following persons:
Other factors include the following:
Children most susceptible to asthma attacks include the following:
Children with a family history of asthma
Children who have allergies
Children who have exposure to secondhand tobacco smoke
What happens during an asthma attack or asthma exacerbation?
Persons with asthma have acute episodes when the air passages in their lungs become narrower, and breathing becomes more difficult. These problems are caused by an over-sensitivity of the lungs and airways.
The lungs and airways overreact to certain triggers causing:
The lining of the airways to become inflamed and swollen.
Tightening of the muscles that surround the airways.
An increased production of mucus.
Breathing becomes harder and may hurt.
Talking and sleeping may be difficult.
There may be coughing sometimes with mucus.
There may be a wheezing or whistling sound, which is typical of asthma. Wheezing occurs because of the rush of air which moves through the narrowed airways.
How is asthma diagnosed?
To diagnose asthma and distinguish it from other lung disorders,doctors rely on a combination of medical history, physical examination, and laboratory tests, which may include the following:
Spirometry. A spirometer is a device used by your doctor that assesses lung function. Spirometry is the evaluation of lung function with a spirometer. The test is performed by blowing as hard as possible into a tube connected to a small machine (a spirometer) that measures the amount of air breathed out and in as well as the speed it is breathed out. This is one of the simplest, most common pulmonary function tests and may be necessary for any or all of the following reasons:
To determine how well the lungs receive, hold, and utilize air
To monitor a lung disease
To monitor the effectiveness of treatment
To determine the severity of a lung disease
To determine whether the lung disease is restrictive (decreased airflow) or obstructive (disruption of airflow)
Peak flow monitoring (PFM). A device used to measure the fastest speed in which a person can blow air out of the lungs. To use a peak flow meter, a person takes a deep breath in and then blows as hard and fast as possible into a mouthpiece. During an asthma or other respiratory flare-up, the large airways in the lungs slowly begin to narrow. This will slow the speed of air leaving the lungs and can be measured by a PFM. This measurement is very important in evaluating how well or how poorly the disease is being controlled.
Chest X-rays. A diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
Blood tests. These tests are done to analyze the amount of carbon dioxide and oxygen in the blood.
What are the triggers that can cause an asthma attack?
According to the CDC, the American Academy of Allergy, Asthma, and Immunology, and other organizations, triggers for asthma include the following:
Respiratory infections and sinusitis
Infections can cause irritation of the airways, nose, throat, lungs, and sinuses, and worsens asthma.
Sensitivity to medications
Strong odors and sprays, such as perfumes, household cleaners, cooking fumes, paints, and varnishes
Chemicals, such as coal, chalk dust, or talcum powder
Air pollutants, such as tobacco smoke, wood smoke, chemicals in the air and ozone
Changing weather conditions, including changes in temperature, barometric pressure, humidity, and strong winds
Chemical exposure on the job, such as occupational vapors, dust, gases, or fumes.
Medications, such as aspirin and additives, such as sulfites, cause up to 20 percent of adult asthmatic attacks as a result of sensitivities or allergies to them. These medications often include:
Other nonsteroidal anti-inflammatory medications, such as ibuprofen, indomethacin, naproxen
Sulfites used as preservatives in food and beverage
Before taking any medication, including over-the-counter medications, consult your doctor.
Strenuous physical exercise can trigger an asthma attack, often because of the inhaled cool and dry air. Long-term strenuous activities, such as long distance running, are most likely to induce asthma, and swimming is the least likely.
GERD, a condition characterized by persistent reflux of stomach acids, is common in individuals with asthma. Symptoms may include heartburn, belching, or spitting up in infants.
Emotional anxiety and nervous stress
Tobacco smoke, whether directly or passively inhaled, has been shown to worsen asthma.
Wood smoke from wood-burning heating stoves and fireplaces can release irritating chemicals, such as sulfur dioxide.
Reactions from stress and anxiety are considered to be more of an effect than a cause. They can cause fatigue, which may affect the immune system and, in turn, increase either asthma symptoms or bring on an attack.
Asthma QuizChildren are more likely to have asthma than are ...Asthma Quiz ►
Prednisone Oral solution
Prednisone Oral tablet
Methylprednisolone Sodium Succinate Solution for injection
Methylprednisolone Oral tablet
Dexamethasone Sodium Phosphate Solution for injection
Dexamethasone Oral tablet
Formoterol Fumarate Nebulizer solution
Methylprednisolone Acetate Suspension for injection
Fluticasone Furoate Nasal spray
Hydrocortisone Topical spray
Fluticasone, Salmeterol Inhaler
Epinephrine Hydrochloride Nasal spray
Aminophylline Oral tablet
Dexamethasone Oral solution
Fluticasone Propionate Topical lotion
Hydrocortisone Rectal enema, suspension
Hydrocortisone Rectal cream
Montelukast Sodium Chewable tablet
Epinephrine Solution for injection
Levalbuterol Tartrate Pressurized inhalation, suspension
Dexamethasone Sodium Phosphate Eye ointment
Triamcinolone Acetonide Nasal spray
Dyphylline Oral tablet
Omalizumab (Hamster) Solution for injection
Montelukast Sodium Oral granules
Terbutaline Sulfate Solution for injection
Terbutaline Sulfate Oral tablet
Salmeterol Xinafoate Inhalation powder
Salmeterol, Xinafoate Inhaler
Metaproterenol Sulfate Nebulizer solution
Metaproterenol Sulfate Inhaler
Metaproterenol Sulfate Oral tablet
Levalbuterol Hydrochloride Nebulizer solution
Formoterol Fumarate Inhalation powder, capsule
Fluticasone, Salmeterol Inhalation powder
Epinephrine Hydrochloride Solution for injection
Epinephrine Hydrochloride Inhalation vapour, solution
Ephedrine Sulfate Solution for injection
Albuterol Sulfate Nebulizer solution
Albuterol Sulfate Oral syrup
Zafirlukast Oral tablet
Montelukast Sodium Oral tablet
Nedocromil Sodium Eye drops, solution
Nedocromil Sodium Inhaler
Cromolyn Sodium Nasal spray, solution
Cromolyn Sodium Eye drops, solution
Cromolyn Sodium Nebulizer solution
Cromolyn Sodium Inhaler
Cromolyn Sodium Oral solution
Prednisolone Sodium Phosphate Oral solution
Prednisolone Oral tablet
Flunisolide Nasal spray
Cortisone Acetate Oral tablet
Budesonide Nebulizer suspension
Budesonide Inhalation powder
Budesonide Oral capsule, gastro-resistant pellets
Beclomethasone Dipropionate Nasal spray
Triamcinolone Acetonide Inhaler
Triamcinolone Acetonide Dental paste
Triamcinolone Oral tablet
Hydrocortisone Acetate Rectal suppository
Hydrocortisone Acetate Rectal foam
Hydrocortisone Sodium Succinate Solution for injection
Hydrocortisone Oral tablet
Fluticasone Propionate Nasal spray
Fluticasone Propionate Inhalation powder
Fluticasone Propionate Inhaler
Betamethasone Valerate Topical foam
Betamethasone Acetate, Betamethasone Sodium Phosphate Suspension for injection
Betamethasone Oral syrup