Is your asthma under control? If you're like most people, you probably think it is. You feel OK most of the time, so you usually don't need medicine. When your asthma flares up, a puff from your trusty emergency inhaler solves the problem -- most of the time, at least.

But experts say that if you have persistent asthma and you're only treating it during attacks, you're not controlling it at all. Anyone who has asthma symptoms more than twice a week during the daytime, or more than two nights a month, should talk to their doctors about preventive treatment.

"A lot of people have this attitude that they don't need to worry about their asthma unless they're having an attack," says Timothy Craig, DO, professor of medicine and pediatrics at Penn State University. "The rest of the time, they ignore it."

Asthma: An Ever-Present Disease

Asthma is a chronic, incurable disease. Even when you feel well, your asthma hasn't gone away. Even if you can't feel it, your airways might still be inflamed. Treating persistent asthma with only occasional puffs from a rescue inhaler is like dealing with a leaky pipe in your basement by mopping up the water on the floor. You're only thinking about the symptom and not treating the underlying cause. Over time, if asthma isn't well controlled it can damage your airways permanently.

Yet while damage to the airways may be irreversible, it is not inevitable. The good news is that there is a lot you can do to prevent serious damage from ever developing.

"When asthma gets correctly diagnosed and treated, most people do very well with the conventional medications we have available," says allergist Jonathan A. Bernstein, MD, associate professor of clinical medicine at the University of Cincinnati College of Medicine.

There may not be a cure for asthma , but by sticking to the right treatment -- avoiding triggers and taking your medicine -- you can regain control and live a full and normal life.

How Asthma Affects Your Airways

Asthma is a complicated disease, and doctors don't completely understand its causes. But it has two main components: inflammation and muscle constriction.

Asthma affects the airways, the bronchial tubes that carry air into the lungs. In people with asthma, the lining of these airways becomes inflamed. No one is sure why this first develops. But certain allergy triggers (like pollen or pet dander) or irritants (like perfumes or cigarette smoke) begin to trigger this swelling.

If you take long-term control medicines -- like inhaled corticosteroids -- you can reduce this swelling and keep the airways healthy. But if your asthma goes untreated, problems develop. Over time, this constant inflammation can destroy the surface layer of the airways, says Hugh H. Windom, MD, associate clinical professor of immunology at the University of South Florida.

"The surface layer acts as a kind of filter," Windom says. "But once it's gone, all of the pollutants and allergens have direct access into the lungs." So asthma can cause damage to the airways that, in turn, makes the asthma worse.

Asthma also affects the muscles that surround the airways. During an attack, these muscles tighten and further restrict the amount of air getting into the lungs.

Eventually, the constant inflammation and muscle constriction can have irreversible effects.

Norman Edelman, MD, a lung specialist and chief medical officer for the American Lung Association, compares it to arthritis . "Arthritis causes swelling," he tells WebMD. "If you don't treat it, that swelling can permanently deform the joints. Asthma works the same way."

Untreated asthma can permanently change the shape of the airways. The tissue of the bronchial tubes becomes thickened and scarred. The muscles are permanently enlarged. And a person may wind up with reduced lung function that can never be healed.

Asthma: A Surprisingly Silent Disease

Asthma is known for its obvious and noisy symptoms: wheezing, gasping, and coughing. But experts say that the typical impression of asthma is not always correct.

"Asthma can sometimes be a silent disease," says Bernstein. "People can walk around with very serious asthma, with significant blockages of their airways, and not show any symptoms."

Windom agrees. "The severity of asthma symptoms really may not reflect the severity of the underlying disease," he says. Even if you feel fine, your asthma may still be damaging your airways -- and you may be closer to a serious attack than you realize.

Even if you do have symptoms, you may not have an accurate impression of how much they affect you.

"There's no question that people with asthma tend to think they have much better control over their condition than they actually do," Edelman tells WebMD.

In a 2005 poll of over 4,500 adults with asthma in the U.S. sponsored by the Asthma and Allergy Foundation, 88% said that their condition was "under control." But experts question their optimistic judgment. About 48% said that their symptoms disturbed their sleep. And 50% said that asthma has made them give up in the middle of a workout. Those are severe symptoms for people who supposedly have their condition "under control."

While many adults have trouble assessing their own asthma, it's a special problem for children. They may not remember life without symptoms.

"It's very easy for symptoms to be missed in kids," says Windom. "I see kids who don't like sports because they can't compete and get short of breath. But their parents don't realize what's going on. They assume that their children are just lazy couch potatoes, or that they just prefer computers to playing outside."

Craig agrees. "Many kids who have always had asthma don't know any better," he tells WebMD. "They think that this is just how things are supposed to be. They don't complain, so no one around them knows about their symptoms."

The Importance of Early Asthma Treatment

Doctors used to have a more relaxed attitude to treating asthma, but experts now agree that it's crucial to get treatment as soon as possible.

"I think just about anyone who treats asthma will tell you that aggressive treatment is the way to go," says Edelman. "It really works."

There are two basic types of medicines. Quick-relief medications, usually in the form of inhalers, swiftly reduce the muscle tightness around the airways, allowing you to breathe easier. You would use a quick-relief medicine during an asthma attack.

Long-term control medicines either calm inflammation or help prevent the airways from closing. They are used daily - not just when you have an asthma attack -- because they work slowly. They prevent rather than treat symptoms, so they're not much help once you are already having an attack.

Inhaled long-term control medicines are usually preferred, but some long-term medicines are also available as pills.

The other important treatment hinges on your own behavior: You need to stay away from the allergens or irritants that trigger your asthma.

By following this treatment approach, the majority of people with asthma can control their symptoms. They can live normal, healthy lives.

Untreated Asthma Leads to Avoidable Suffering

If asthma is so treatable, why do 5,000 people in the U.S. die from it every year? Why are 70,000 people hospitalized for asthma every year?

The simple answer is that while good asthma treatments are available, many people aren't using them. Not taking your medicine can have serious consequences. "We think that poor or irregular asthma treatment puts people at greater risk of more serious or irreversible damage," says Windom.

Part of the fault lies with doctors, Windom tells WebMD. He says that many doctors don't monitor their asthma patients well enough. Too often, he says, they treat the condition based only on the patient's impression of his or her health, which is often incorrect. He believes that doctors should pay more attention to objective analyses, like breathing tests with peak flow meters.

"Going by a patient's impression -- instead of getting objective measures -- would never be accepted for treating other chronic conditions, like diabetes," Windom says.

But a large part of the problem is that people with asthma are not following their doctor's recommendations. Many only treat the flare-ups of asthma and don't think of it as a chronic disease.

"We have data that shows that people tend to use their long-term asthma treatment for two to three months at a time," says Windom. "But by then they feel better, and they never get the prescription refilled. The pharmacy records show it."

In fact, one survey conducted by the CDC in 2001 found that less than half of people with asthma said that they had a routine check-up with a doctor in the previous year.

Craig says that some patients go through a regular cycle. "It's very common for people to have a scare, like a trip to the ER, and then become diligent with their asthma treatment for a few months," he tells WebMD. "But then their diligence wanes and they stop taking their medication." Gradually, their condition gets worse until they have a crisis. Then the cycle repeats.

When Living With Asthma, Demand the Best Treatment

If you're suffering from asthma now, understand that you can feel better. Doctors have treatments that will help.

Of course, many things can get in the way of good treatment. One of them is the price. Experts agree that the costs of many asthma medications have become very high in recent years. According to the 2005 Health Costs Survey sponsored by the Kaiser Family Foundation, the Harvard School of Public Health, and USA Today, 43% of all people with asthma said that, in the past year, they could not afford their treatment.

If the price is a problem for you, talk honestly with your doctor. See if you can get some free samples. Ask about assistance programs offered by pharmaceutical companies or by your state.

Whatever you do, don't put off getting treatment. Delaying might make your asthma worse.

"If you put off treatment with inhaled steroids too long, you could wind up with irreversible lung disease," says Craig.

So you need to take charge of your health care and fight for the best treatment you can get. Don't settle for a life restricted by symptoms. Don't settle for treatment that isn't helping.

"Demand that you get aggressive treatment of your asthma," says Edelman. "There is no reason for you to be suffering. You have the right to feel well."