What do each of these individuals have in common: First, an 18-year-old suddenly develops wheezing and shortness of breath when visiting his grandmother who happens to have a cat. Second, a 30-year-old woman has colds that "always go into her chest," causing coughing and difficulty breathing. Lastly, a 60-year-old man develops shortness of breath with only slight exertion even though he has never smoked. The answer is that they all have asthma. These are some of the many faces of asthma.
Most researchers believe that the different patterns of asthma are all related to one condition. But some researchers feel that separate forms of lung conditions exist. There is currently no cure for asthma and no single exact cause has been identified. Therefore, understanding the changes that occur in asthma, how it makes you feel, and how it can behave over time is vital. This knowledge can empower people with asthma to take an active role in your own health.
Myths, facts, and statistics about asthma
Before we present the typical symptoms of asthma, we should dispel some common myths about this condition. This is best achieved by conducting a short true or false quiz.
- T or F - Asthma is "all in the mind."
- T or F - You will "grow out of it."
- T or F - Asthma can be cured, so it is not serious and nobody dies from it.
- T or F - You are likely to develop asthma if someone in your family has it.
- T or F - You can "catch" asthma from someone else who has it.
- T or F - Moving to a different location, such as the desert, can cure asthma.
- T or F - People with asthma should not exercise.
- T or F - Asthma does not require medical treatment.
- T or F - Medications used to treat asthma are habit-forming.
- T or F - Someone with asthma can provoke episodes anytime they want in order to get attention.
Here are the answers:
- F - Asthma is not a psychological condition. However, emotional triggers can cause flare-ups.
- F - You cannot outgrow asthma. In about 50% of children with asthma, the condition may become inactive in the teenage years. The symptoms, however, may reoccur anytime in adulthood.
- F - There is no cure for asthma, but the disease can be controlled in most patients with good medical care. The condition should be taken seriously, since uncontrolled asthma may result in emergency hospitalization and possible death.
- T - You have a 6% chance of having asthma if neither parent has the condition, a 30% chance if one parent has it, and a 70% chance if both parents have it.
- F - Asthma is not contagious.
- F - A new environment may temporarily improve asthma symptoms, but it will not cure asthma. After a few years in the new location, many people become sensitized to the new environment and the asthma symptoms return with the same or even greater intensity than before.
- F - Swimming is an optimal exercise for those with asthma. On the other hand, exercising in dry, cold air may be a trigger for asthma in some people.
- F - Asthma is best controlled by having an asthma management plan designed by your doctor that includes the medications used for quick relief and those used as controllers.
- F - Asthma medications are not addictive.
- F - Asthma attacks cannot be faked.
What is asthma?
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). The airways may become "twitchy" and remain in a state of heightened sensitivity. This is called "bronchial hyperreactivity" (BHR). It is likely that there is a spectrum of bronchial hyperreactivity in all individuals. However, it is clear that asthmatics and allergic individuals (without apparent asthma) have a greater degree of bronchial hyperreactivity than nonasthmatic and nonallergic people. In sensitive individuals, the bronchial tubes are more likely to swell and constrict when exposed to triggers such as allergens, tobacco smoke, or exercise. Amongst asthmatics, some may have mild BHR and no symptoms while others may have severe BHR and chronic symptoms.
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.
The scope of the problem
Asthma is now the most common chronic illness in children, affecting one in every 15. In North America, 5% of adults are also afflicted. In all, there are about 1 million Canadians and 15 million Americans who suffer from this disease.
The number of new cases and the yearly rate of hospitalization for asthma have increased about 30% over the past 20 years. Even with advances in treatment, asthma deaths among young people have more that doubled.
How does asthma affect breathing?
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 hyperreactivity.
Inflammation
The first and most important factor causing narrowing of the bronchial tubes is inflammation. 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 inflammation occurs in response to an allergen or irritant and results from the action of chemical mediators (histamine, leukotrienes, and others). The inflamed tissues produce an excess amount of "sticky" mucus into the tubes. The mucus can clump together and form "plugs" that can clog the smaller airways. Specialized allergy and inflammation cells (eosinophils and white blood cells), which accumulate at the site, cause tissue damage. These damaged cells are shed into the airways, thereby contributing to the narrowing.
Bronchospasm
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. Chemical mediators and nerves in the bronchial tubes cause the muscles to constrict. Bronchospasm can occur in all humans and can be brought on by inhaling cold or dry air.
Hyperreactivity (hypersensitivity)
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.
