Definition of asthma

Asthma is a chronic condition in your lungs that has two main components. When you have asthma, two things happen inside your lungs --- constriction, the tightening of the muscles surrounding the airways, and inflammation, the swelling and irritation of the airways. Constriction and inflammation cause narrowing of the airways, which may result in symptoms such as wheezing, coughing, chest tightness, or shortness of breath. Furthermore, there is increasing evidence that, if left untreated, asthma can cause long-term loss of lung function.

When you have asthma and are exposed to a trigger, the airways leading to the lungs become more inflamed or swollen than usual, making it harder for you to breathe. The airways also get smaller due to a tightening of the muscles surrounding the airways, and they get "stuffed up" due to a build-up of mucus.

Several triggers can cause your asthma symptoms to flare up, and may include allergies, infections, and strong odors or fumes that you may come in contact with at your home or office. Once you are exposed to a trigger and have a reaction, your airways also become more sensitive to other triggers. So, it's important to manage your asthma every day. Airway inflammation may always be there ---even when you are not having a lot of symptoms.

Prevalence of asthma
Seventeen million Americans, five million of them children have asthma. The incidence has increased over 50% in the last fifteen years. There are over five hundred thousands hospitalizations each year, making asthma on of the top five most expensive diseases our healthcare system must cover.

Despite the prevalence, however, asthma can be controlled. Our goal, almost universally met, is that every patient enjoys a completely full life without any limitations. With understanding of the disease process and of the various medications available, patients should be able to meet this goal. Education and record keeping are key to achieving this goal.

Categorizing Asthma
Asthma is often put into categories or groups based on the "triggers" that cause the asthma symptoms or attacks. These categories or types of asthma are:

Allergic asthma
Allergic asthma is triggered by an allergic reaction to allergens such as pollens or pet dander. People with this type of asthma typically have a personal and/or family history of allergies (such as hay fever) and/or eczema (skin problem resulting in itching, a red rash, and sometimes small blisters).

Seasonal asthma
Tree pollen, grass pollen, molds spores or flowers releasing pollen can all be triggers of seasonal asthma. For example, some people find that their asthma is worse in the spring when there is an increase in flowering plants. Others find their asthma is worse in the late summer or early fall when ragweed and leaves from trees are more likely to cause problems. With careful attention and a calendar, it is simple to identify a root cause of one's asthma without the need for painful skin testing.

Non-allergic asthma
For some people with asthma, asthma attacks have nothing to do with allergies. Although these people get the same symptoms and have the same changes in their airways as patients with allergic asthma, their asthma is not triggered by allergies. Like any patient with asthma, however, asthma attacks may be triggered or made worse by one or more non-allergic asthma triggers including materials (irritants) in the air you breathe, such as tobacco smoke, wood smoke, room deodorizers, pine odors, fresh paint, household cleaning products, cooking odors, workplace chemicals, perfumes, and outdoor air pollution. Respiratory infections, such as the common cold, Influenza, or a sinus infection may also give you symptoms. Finally, exercise, cold air, sudden changes in air temperature, and even gastro esophageal reflux (heartburn) may be triggers for people with non-allergic asthma.

Exercise-induced asthma
Exercise-induced asthma (EIA) simply refers to asthma symptoms that are triggered by exercise or physical activity. These symptoms are usually noticed during or shortly after exercise. Exercising in the winter seems to be particularly bad for patients with this type of asthma as cold air and sudden changes in the temperature of the air one breathes are normally found at this time of year.

Nocturnal asthma
Can occur in a patient with any type of asthma. It refers to asthma symptoms that seem worse in the middle of the night, typically between 2 and 4 AM.

Things that can cause asthma symptoms to get worse at night may include sinus infections or postnasal drip caused by allergens like dust mites or pet dander. Your body clock may also play some role: levels of substances your body makes like adrenaline and steroids, both of which protect against asthma, are lowest between 4 and 8 AM, making it easier for people with asthma to get symptoms during these times of the night.

November 2001