Asthma

Diagnosis

Your doctor will ask questions to determine the nature and severity of your symptoms, and your risk factors. Your doctor will ask questions about your pattern of symptoms and any family history of asthma or allergies that can support the likelihood that you have asthma. Your doctor will also ask about the frequency and severity of your symptoms, about medications that you take, and about whether or not you are exposed to the kinds of triggers that are known to cause asthma in others, such as viral respiratory infections and allergens or irritants.

Your doctor will perform a physical examination focusing on the upper respiratory tract, chest, and skin. Your doctor will look for hyperexpansion of the thorax (particularly in children), hunched-looking shoulders, and chest deformity, as these are physical findings that suggest asthma. Wheezing sounds during normal breathing or a prolonged phase of forced exhalation also may suggest asthma.

Your doctor will also look for signs of an allergic reaction, such as increased nasal secretion, mucosal swelling, nasal polyps, or allergic skin conditions.

Lung function tests are usually performed to confirm asthma and to determine its severity. Spirometry is a lung test doctors use to establish whether you have airflow obstruction, and whether it is reversible. Very precise measurements of inhaled and exhaled air are measured when you blow into a device called a spirometer. Spirometry is done periodically to assess obstruction and airway function.

When asthma is suspected, but previous spirometry measurements were normal or almost normal, doctors can use other methods to diagnose or rule out asthma. These include provoking the bronchial tubes (bronchoprovocation) with methacholine, histamine, or exercise followed by spirometry.

You can perform tests yourself in your own home to monitor your progress [Figure 2]. Peak flow meters also are helpful for measuring airflow obstruction. A peak flow meter can help to discover if there is airway narrowing hours, and perhaps even days before asthma symptoms appear. Peak flow meters are inexpensive, simple, and portable tests that you can use to monitor yourself between doctor visits. By keeping records of the measurements, you and your doctor can learn if the particular treatment plan you are using is working well, what makes the asthma worse, and when to add or drop medications. You obtain the measurements by blowing into a tube and reading the corresponding number. Peak flow numbers are color-coded into zones of red (danger), yellow (warning), and green (good), and show you how well your asthma is being controlled.

Figure 2. Peak flow meter

A peak flow meter is a device that measures how well air moves out of your lungs. The peak flow meter can be used to find out if there is airway narrowing hours, even days, before you have any symptoms of asthma. By taking medicine before symptoms develop, you may be able to stop the attack from becoming serious. Children younger than three are usually not good candidates for peak flow devices, but anyone older should consider using one.

How to use a peak flow meter:

• Place the indicator at the base of the numbered scale
• Stand up
• Take a deep breath
• Place the meter in your mouth and close your lips around the mouthpiece
• Do no put your tongue inside the hole
• Blow out as HARD and FAST as you can
• Write the number down that you get
• Repeat these steps two more times
• Write down the highest of the three numbers achieved

FIND YOUR PERSONAL BEST PEAK FLOW NUMBER

Your personal best number is the highest peak flow number you can achieve over a two-week period when your asthma is under good control, meaning you feel fine and do not have asthma symptoms.

Take peak flow readings twice a day for two weeks, in the morning when you wake up and about 10 to 12 hours later. If you take inhaled beta2-agonist medication, take your readings before and after you inhale it.

Keep a diary of your readings.

Once you know your personal best number, your health care professional will assign a zoning system to your range of numbers that will tell you what to do. The zoning system is set up like a traffic light:

Green Zone: (80% to 100% of your personal best number) means that everything is going great. No asthma symptoms are present and you may take your medications as usual.

Yellow Zone: (50% to 80% of your personal best number) means be cautious. You may be having an episode of asthma that requires an increase or a change in your medications. Your asthma may not be under control. Inform your doctor.

Red Zone: (below 50% of your personal best number) signals a medical alert. You must take an inhaled beta2-agonist right away and call your doctor immediately. You need medical attention as soon as possible.

Your doctor will help you create a plan of what to do when your peak flow readings change and how to react in the case of an emergency.

Prevention and Screening

Know what triggers your asthma. You can help to prevent asthma attacks by avoiding things known to make your asthma worse. Discuss asthma triggers with your doctor and take steps to avoid them. Specific triggers may vary from individual to individual.

Avoid cigarette smoke. Smoking cigarettes will make asthma symptoms worse, and secondhand smoke may spur an asthma attack. Your doctor can suggest ways to help you stop smoking. Ask family members to stop smoking as well. Do not permit anyone to smoke in your home or around you. Protect children by making sure no one smokes at a children's day care center.

Reduce your exposure to dust mites. Frequent vacuuming is beneficial, but will not completely remove house dust mites from carpeting or upholstered furniture. When vacuuming, use a dust mask, a double-layered or microfilter vacuum cleaner bag, or a vacuum cleaner with a high efficiency air filtration filter, known as a HEPA filter. Even better, find someone else to do the vacuuming and stay out of the rooms while they are being cleaned.

Encase your bed mattress and pillows in special allergen-impermeable dust-proof covers. If you don't use dust-proof covers on your pillows, wash your pillows weekly in water hotter than 130°F (54.4°C). Sheets and blankets also should be washed weekly in hot water. Avoid resting on fabric-covered furniture. Having hardwood floors rather than wall-to-wall carpeting may help prevent dust from accumulating. Because high indoor humidity promotes dust mites, try to decrease indoor humidity to less than 50% by using a dehumidifier or a central air-conditioning system. Remove any carpets that are placed on concrete, as mold could grow there easily.

Protect yourself from animal dander. If you own pets, you can take steps to minimize your exposure to animal dander. If you have a yard or patio, keep furred or feathered pets outside, weather permitting. If animals must live inside, keep them outside the bedroom and make sure the door is closed at all times. Keep pets out of rooms with carpets and fabric-covered furniture. Cover the air vents in the bedroom with a filter.

Take necessary measures to prevent cockroaches. Many people with asthma are allergic to dried droppings and remains of cockroaches. Poison bait or traps can help control the pests. Food and garbage should not be left exposed, but kept in closed containers. Vigorous and frequent extermination procedures are required to remove cockroaches. If pesticide spray is used, be sure to stay out of the room until the odor is gone.

Avoid exposure to pollen and outdoor mold. To avoid exposure to pollens from trees, grass, or weeds, and from outdoor molds, try to keep your windows closed during the season when pollen or mold spore counts are high. During allergy season, remain indoors with the windows closed; especially during the morning when pollen and mold spore counts are at their highest.

Reduce moisture to help eliminate indoor mold. Reduce indoor humidity to less than 50% by using air conditioners or dehumidifiers. Fix all leaks and eliminate any other water sources that are associated with mold growth. Clean moldy surfaces with a product that contains bleach.

Reduce exposure to other irritants. Try to avoid using wood-burning stoves, fireplaces, and kerosene heaters. Stay away from other irritants, such as perfumes, talcum powder, hair spray, paints, or any other substance that emits noxious fumes.

Get a yearly influenza (flu) shot to protect yourself against influenza.