Asthma is a disease in which the airways become blocked or narrowed. These effects are usually temporary, but they cause shortness of breath, breathing trouble and other symptoms. If an asthma attack is severe, a person may need emergency treatment to restore normal breathing.

About 15 million Americans have asthma, including nearly five million children under age 18. This health problem is the reason for nearly half-a-million hospital stays each year. People with asthma can be of any race, age or sex. Its treatment costs billions of dollars each year.

Despite the far-reaching effects of asthma, much remains to be learned about what causes it and how to prevent it. Although asthma can cause severe health problems, in most cases treatment can control it and allow a person to live a normal and active life.

Things in the environment trigger an asthma attack. These triggers vary from person to person, but common ones include cold air, exercise, allergens (things that cause allergies) such as dust mites, mold, pollen, animal dander or cockroach debris, and some types of viral infections.

When you breathe in, air travels through your nose and/or mouth through a tube called the trachea (sometimes referred to as the "windpipe"). From the trachea, it enters a series of smaller tubes that branch off from the trachea. These branched tubes are the bronchi, and they divide further into smaller tubes called the bronchioles. It is in the bronchi and bronchioles that asthma has its main effects.

Here is how the process occurs. When the airways come into contact with an allergen, the tissue inside the bronchi and bronchioles becomes inflamed (inflammation). At the same time, the muscles on the outside of the airways tighten up (constriction), causing them to narrow. A thick fluid (mucus) enters the airways, which become swollen. The breathing passages are narrowed still more, and breathing is hampered.

The process just described can be normal, up to a point. Everyone's airways constrict somewhat in response to irritating substances like dust and mold. But in a person with asthma, the airways are hyper-reactive. This means that their airways overreact to things that would just be minor irritants in people without asthma.

To describe the effects of asthma, some doctors use the term "twitchy airways." This is a good description of how the airways of people with asthma are different from those without the disease. Not all patients with hyperreactive airways have symptoms of asthma, though.

We still do not know what causes some people to develop asthma. Research shows that a family history of asthma or allergies, a specific allergy in the child or cigarette smoking during pregnancy may increase the likelihood that a person will develop asthma early in life.

One of the most common causes of asthma symptoms in children five years old and younger is a respiratory virus. Although both adults and children experience respiratory infections, children have more of them and some preschool children are plagued with viral infections. At least half of children with asthma show some sign of it before the age of five. Viruses are the most common cause of acute asthma episodes in infants six months old or younger.

Asthma symptoms can look like symptoms of other illnesses or diseases. Croup, bronchitis, epiglottis, cystic fibrosis, pneumonia, bronchiectasis, upper respiratory tract viruses, gastroesophageal reflux, congenital abnormalities or even a foreign body inhaled by the child-all have some of the same symptoms of asthma.

Signs of asthma in a baby or toddler include:

• Noisy breathing or breathing increased 50 percent above normal
• Normal respiration rates:
• newborns 30-60 breaths/minute
• 1st year 20-40 breaths/minute
• 2nd year 20-30 breaths/minute
• Wheezing or panting with normal activities
• Lethargy, disinterest in normal or favorite activities
• Difficulty sucking or eating
• Crying sounds softer, different

Parents may not be aware that asthma symptoms are becoming serious, possibly leading to a medical emergency. If your child demonstrates any of the symptoms listed below, seek medical help immediately:

• Breathing increased 50 percent or more above normal
• Difficulty with sucking or eating that leads to a refusal to eat altogether
• Cyanosis - very pale or blue coloring in face, lips, fingernails
• Rapid movement of nostrils Ribs or stomach moving in and out deeply and rapidly
• Expanded chest that does not deflate when child exhales
• Failure to respond to or recognize parents

Diagnosing asthma in very young children is difficult. Since they are not able to communicate, they cannot describe how they are feeling. A baby's fussy behavior could mean many things; however, toddlers and preschoolers often continue to be fairly active in spite of increasing chest tightness or difficulty with breathing.

To help the pediatrician make a correct diagnosis, parents must provide information about family history of asthma or allergies, the child's overall behavior, breathing patterns and responses to foods or possible allergy triggers. Lung function tests - often used to make a definitive asthma diagnosis-are very hard to do with young children. Instead, the physician may see how the child responds to medications to improve breathing. Blood tests, allergy testing and x-rays may be done to gather additional information.

Using all this information, the doctor then can make the best diagnosis. Parents may be referred to a pediatric allergist or pulmonologist (lung specialist) for specialized testing or treatment.

Babies or toddlers can use most medications used for older children and adults. The dosage, of course, is lower, and the way the medication is given is different. Inhaled medications are preferred because they generally act more rapidly to reduce symptoms and produce fewer side effects.

Medications to treat asthma symptoms in infants and toddlers are usually given in a tasty liquid form or with a nebulizer. A nebulizer (sometimes referred to as a "breathing machine") is a small machine that uses forced air to create a "medication mist" for the baby to breath through a small face mask. Nebulizer treatments take about 10 minutes and are given several times each day until symptoms decrease. Although a nebulizer treatment is gentle, babies and young children often are frightened by the mask and fight the treatment at first.

Some toddlers are able to use an inhaler containing asthma medication with a spacer and mask attachment. A spacer is a small tube, or "aerochamber," which holds the medication released by the inhaler fitted into it. The inhaler/spacer device allows children to breathe in the medication at their own speed plus spacers add to medication possibilities.

Various medications are used to treat asthma. Bronchodilators (Proventil, Ventolin) are "quick relief" medications, opening up airways immediately to make breathing easier. "Long term control" medications such as corticosteroids (Prelone, Pediapred) or cromolyn sodium (Intal) help keep asthma symptoms at a minimum. Most people with asthma, including very young children, use a combination of medications, depending on severity and frequency of symptoms. Work with their health care providers to develop an asthma care management plan for your child.

You can reduce asthma symptoms by controlling allergy triggers in your child's environment. Concentrate on the bedroom, where very young children spend as much as 12-18 hours each day. Cover the pillows, mattress and box springs in allergen-proof casings. Wash bed linens weekly in 130-degree water. Use washable area carpets. Buy only washable stuffed animals. Vacuum weekly or more. Don't allow pets in the bedroom/house. Restrict smoking in the house (even if someone smokes in the basement of a multi-storied house, smoke filters through the vents to all parts of the house). Use air purifiers with a HEPA filter (only for animal dander sensitive children if there is an animal in the home).

There is some evidence that breast-feeding helps prevent children from developing eczema and food allergies, but probably does not reduce asthma. Also, if there is a history of allergies in your family or if you think your baby may have allergies, slowly introduce new foods in his/her diet so you can monitor responses. Be especially careful of the foods known to cause an allergic response in many people: nut-based foods (like peanut butter), dairy products, soy, fish, shellfish, wheat products and eggs. Watch for hidden ingredients in packaged foods.

When a very young child has a chronic illness, parents can feel stretched to their limits as they try to manage. Consider these tips for coping:

• Learn the warning signs for increasing asthma in infants and toddlers. Know your child's particular asthma symptom "pattern."
• Develop an asthma care management plan with your child's physician. Make sure the plan provides guidelines to follow if asthma symptoms get worse. Understand when your child's symptoms require emergency care.
• Follow your asthma care plan every day! Don't alter from the plan until you consult your healthcare provider. Even if your child's symptoms are gone, stick with the plan until you discuss changes with the doctor.
• Get regular check-ups to help reduce your anxiety.
• Teach your toddler or preschooler to tell you when they are not feeling well.
• Work out an emergency plan of action to follow if your child has a serious asthma episode. What hospital will you use? (Be sure your doctor uses that hospital and it is in your health care plan.) Who will take care of your other children? How does your medical coverage provide for emergency care?

Above all, don't let your child's asthma become the focus of your relationship! If you use good health care practices to manage your baby or toddler's asthma, you'll be able to think less about asthma and enjoy your child more!