How Asthma Is Diagnosed
Asthma is a common chronic health problem in the US and many other countries around the world. It is becoming especially common in children. But people of any age can develop asthma, even senior citizens.
However, asthma symptoms are often similar to the symptoms of other respiratory illnesses. So, how does a doctor make the decision that what you have is asthma?
In adults, doctors can rely on a history of your symptoms, i.e., when they occur, how often, and how long they last. The key symptoms your doctor will ask you about include:
- Cough, which is worse at night
- Frequent wheezing
- Frequent shortness of breath
- Frequent chest tightness
Another question your doctor may ask is if you notice your symptoms get worse with exposure to any of the following factors:
- Viral infection
- Animals with either fur or feathers
- House dust mites (found in mattresses, overstuffed furniture, carpets, pillows)
- Mold, either outdoors or indoors
- Tobacco or wood smoke
- Pollen from grass, trees, or weeds
- Changes in weather, especially cold weather
- Strong laughing or crying or emotional stress
- Chemical fumes or dusts
Also, if your symptoms get worse at night and prevent you from sleeping, that's a strong indication that asthma may be at work on your airways.
The doctor will also take a look at your family history of allergies and asthma, because asthma does tend to "run" in families. And even if no one in your family ever had asthma, but they did have allergies, you are probably at a higher risk for asthma than people who don't have a family history of allergies.
Besides your personal and family health history, the doctor may perform some tests to help him or her make the diagnosis. A peak flow meter is a device that doctors can use to measure how well your lungs are working. It's a handheld device that you blow into. It measures what is called Peak Expiratory Flow, or PEF for short. When the PEF varies by 20 percent or more between the first thing in the morning and early afternoon, your doctor will suspect asthma.
Another test that is sometimes used is called spirometry. This is a machine that can measure the amount and rate of air you breathe with more accuracy than a peak flow meter.
Diagnosing asthma in young children is harder. To begin with, a child may not be able to describe how he or she is feeling as well as an adult can. So, the doctor will need to rely on the observations of the parent. One of the most common symptoms of asthma in children is a chronic cough, so if you notice that in your child, talk with your doctor.
Doctors may not always be able to say for sure a child has asthma, so they may simply tell you that your child has "breathing problems." Nevertheless, your doctor will probably treat your child as if he or she did have asthma.
Once a doctor has made a diagnosis of asthma, then he or she will go on to classify your level of asthma. Classifying asthma helps guide the doctor in developing your asthma treatment plan. Here are the 4 main classifications:
Mild intermittent: With this classification, significant asthma symptoms generally occur no more than two times a week, and in between you have no symptoms. Symptoms occur at night during sleeping hours less than twice a month. When you do have symptoms, they can last anywhere from a few hours to a few days, and the intensity may vary. If you use a peak flow meter, your PEF will usually be within 20% of your personal best level.
Mild persistent: At this level of asthma, symptoms occur more than twice a week, but not as often as everyday. But when you are having symptoms, they often interfere with your usual activities. Symptoms are waking you up at night more than twice a month. If you use a peak flow meter, your PEF will usually be within 20 to 30 percent of your personal best level.
Moderate persistent: At this level, symptoms occur every day and you need to use a quick-relief inhaler at least once a day too, in order to relieve your symptoms. Severe flare-ups, which occur more than twice a week, limit your activities and may last for days. And you're probably waking up at night with symptoms at least once a week. Your PEF will generally be 30 percent of your personal best.
- Severe persistent: At this level, symptoms are continuous, despite use of your quick-relief inhaler. Physical activity is limited by your symptoms and your PEF is more than 30% off your personal best. Asthma symptoms are interfering with sleep on a regular basis. This is a picture of asthma out of control and should be addressed immediately with medical treatment.
Some different ways of classifying and treating asthma are being studied, and are based not only on your symptoms, but also on your response to treatment.
If you are noticing any of the hallmark symptoms of asthma on a frequent or continuous basis, it's a good idea to check with your doctor to see if you might have a diagnosis of asthma. Asthma doesn't have to interfere with your lifestyle, provided you get effective and timely treatment.
- Mild intermittent: With this classification, significant asthma symptoms generally occur no more than two times a week, and in between you have no symptoms. Symptoms occur at night during sleeping hours less than twice a month. When you do have symptoms, they can last anywhere from a few hours to a few days, and the intensity may vary. If you use a peak flow meter, your PEF will usually be within 20% of your personal best level.