Asthma is a chronic inflammation of the bronchial tubes (airways) that causes swelling and narrowing (constriction) of the airways. The result is difficulty breathing. The bronchial narrowing is usually either totally or at least partially reversible with treatments.
Bronchial tubes that are chronically inflamed may become overly sensitive to allergens (specific triggers) or irritants (nonspecific triggers).
Asthma affects people differently. Each individual is unique in their degree of reactivity to environmental triggers. This naturally influences the type and dose of medication prescribed, which may vary from one individual to another.
Asthma causes a narrowing of the breathing airways, which interferes with the normal movement of air in and out of the lungs. Asthma involves only the bronchial tubes and does not affect the air sacs or the lung tissue. The narrowing that occurs in asthma is caused by three major factors: inflammation, bronchospasm, and hyper-reactivity.
The bronchial tubes become red, irritated, and swollen. This inflammation increases the thickness of the wall of the bronchial tubes and thus results in a smaller passageway for air to flow through. The inflamed tissues produce an excess amount of "sticky" mucus into the tubes.
The muscles around the bronchial tubes tighten during an attack of asthma. This muscle constriction of the airways is called bronchospasm. Bronchospasm causes the airway to narrow further.
In patients with asthma, the chronically inflamed and constricted airways become highly sensitive, or reactive, to triggers such as allergens, irritants, and infections. Exposure to these triggers may result in progressively more inflammation and narrowing.
The combination of these three factors results in difficulty with breathing out, or exhaling. As a result, the air needs to be forcefully exhaled to overcome the narrowing, thereby causing the typical "wheezing" sound. People with asthma also frequently "cough" in an attempt to expel the thick mucus plugs. Reducing the flow of air may result in less oxygen passing into the bloodstream, and if very severe, carbon dioxide may dangerously accumulate in the blood.
Which triggers cause an asthma attack?
Asthma symptoms may be activated or aggravated by many agents. Not all asthmatics react to the same triggers. Additionally, the effect that each trigger has on the lungs varies from one individual to another. In general, the severity of your asthma depends on how many agents activate your symptoms and how sensitive your lungs are to them. Most of these triggers can also worsen nasal or eye symptoms.
Triggers fall into two categories:
nonallergens -- mostly irritants (nonspecific).
Once your bronchial tubes (nose and eyes) become inflamed from an allergic exposure, a re-exposure to the offending allergens will often activate symptoms. These "reactive" bronchial tubes might also respond to other triggers, such as exercise, infections, and other irritants. The following is a simple checklist.
Common asthma triggers:
year-round dust mites, molds, pets, and insect parts
foods, such as fish, egg, peanuts, nuts, cow's milk, and additives, such as sulfites
work-related agents, such as latex, epoxides, and formaldehyde
About 80% of children and 50% of adults with asthma also have allergies.
respiratory infections, such as those caused by viral "colds," bronchitis, and sinusitis
drugs, such as aspirin, other NSAIDs (nonsteroidal antiinflammatory drugs), and beta blockers (used to treat blood pressure and other heart conditions)
outdoor factors, such as smog, weather changes, and diesel fumes
indoor factors, such as paint, detergents, deodorants, chemicals, and perfumes
GERD (gastroesophageal reflux disorder)
exercise, especially under cold dry conditions
work-related factors, such as chemicals, dusts, gases, and metals
emotional factors, such as laughing, crying, yelling, and distress
hormonal factors, such as in premenstrual syndrome
Typical asthma symptoms and signs
The symptoms of asthma vary from person to person and in any individual from time to time. It is important to remember that many of these symptoms can be subtle and similar to those seen in other conditions. All of the symptoms mentioned below can be present in other respiratory, and sometimes, in heart conditions. This potential confusion makes identifying the settings in which the symptoms occur and diagnostic testing very important in recognizing this disorder.
The following are the four major recognized asthma symptoms:
Shortness of breath, especially with exertion or at night
Wheezing is a whistling or hissing sound when breathing out
Coughing may be chronic, is usually worse at night and early morning, and may occur after exercise or when exposed to cold, dry air
Chest tightness may occur with or without the above symptoms
Asthma is classified according to the frequency and severity of symptoms, or "attacks," and the results of pulmonary (lung) function tests.
30% of affected patients have mild, intermittent (less than two episodes a week) symptoms of asthma with normal breathing tests
30% have mild, persistent (two or more episodes a week) symptoms of asthma with normal or abnormal breathing tests
40% have moderate or severe, persistent (daily or continuous) symptoms of asthma with abnormal breathing tests
Acute asthma attack
An acute, or sudden, asthma attack is usually caused by an exposure to allergens or an upper-respiratory-tract infection. The severity of the attack depends on how well your underlying asthma is being controlled (reflecting how well the airway inflammation is being controlled). An acute attack is potentially life-threatening because it may continue despite the use of your usual quick-relief medications (inhaled bronchodilators). Asthma that is unresponsive to treatment with an inhaler should prompt you to seek medical attention at the closest hospital emergency room or your asthma specialist office, depending on the circumstances and time of day. Asthma attacks do not stop on their own without treatment. If you ignore the early warning signs, you put yourself at risk of developing status asthmaticus.
Prolonged attacks of asthma that do not respond to treatment with bronchodilators are a medical emergency. Physicians call these severe attacks "status asthmaticus," and they require immediate emergency care
The presence of wheezing or coughing in and of itself is not a reliable standard for judging the severity of an asthma attack. Very severe attacks may clog the tubes to such a degree that the lack of air in and out of your lungs fails to produce wheezing or coughing.
Guide To Asthma Prevention
Although there are many triggers that can set of an asthma attack, you can protect yourself by using appropriate prevention techniques. These techniques are different for each trigger and require a clear understanding of the underlying allergens or irritants. A few ways in which you can prevent an asthma attack are as follows:
1) Prepare An Asthma Plan - Keep in mind that asthma triggers, attack intensity, frequency and symptoms differ from person to person. A specific plan will help you in understanding the allergens and irritants which can trigger an attack and how you can protect yourself against them. Along with your doctor you can prepare a customized plan to manage your asthma and seek vital tips on how to deal with it in case of an acute attack.
2) Identifying Asthma Triggers And Taking Preventive Measures - There are a number of indoor and outdoor allergens and irritants that can trigger an asthma attack. It is necessary to find out which of these causes or worsens your illness. With a clear understanding of these triggers, you can take appropriate preventive strategies against them
Cigarette smoking should be stopped. This will not only be helpful to you but also your family members and friends.
3) Keep Your Surroundings Clean - Controlling the factors which can trigger an attack, is one of the best ways of asthma prevention. People with asthma should strive to keep their house free from dirt, dust, pollen and mold. A clean home means clean air and clean air reduces the possibility of triggering future attacks.
4) Taking Your Medicines Correctly And Regularly - Asthma patients are given medicines for asthma attacks as well as medicines to prevent attacks. It is important to take these medicines regularly and in the prescribed doses to achieve the best possible results. Also you should not discontinue or alter the prescribed medications yourself simply because you find an improvement in your asthma. This should be done only after consultation with your physician.
Also by recognizing any early warning signals of an impending attack like coughing or shortness of breath, you can prevent an asthma attack.