How is asthma diagnosed?
Asthma diagnosis is usually not difficult. A detailed account of the patient’s symptoms is often sufficient to establish the diagnosis.
If you have coughing, wheezing, shortness of breath or tightness of the chest, you should see your physician, who will take steps to determine whether you have asthma. Asthma symptoms are not specific, and some patients with symptoms typical of asthma may actually have another medical condition.
Asthma is diagnosed based on a personal medical history, physical examination, lung function tests and laboratory tests.
1. Personal medical history: Your physician will look for typical symptoms of asthma in your medical history, such as, wheezing or coughing. Your history also provides your physician some additional clues on asthma, such as, your allergies or your familial tendency towards asthma. Some of the typical questions in this category include:
• What type of symptoms have you had? How frequent?
• How long have you had symptoms of asthma?
• How many nights per week do you wake up with breathlessness, cough or wheeze?
• Do you get cough or wheeze after exercise?
• Have you recently had a cold, sinus infection or other infection? For how long?
• Do you or other members of your family have allergies?
• Do you have a pet or materials in your house that might trigger allergies?
• Are you exposed to chemicals or other unusual substances at work?
• Are you exposed to airborne allergens or pollutants?
• Have you recently moved, taken a vacation, changed your job or experienced a transition that might be stressful?
• Have you had asthma medications? What type? How frequent?
2. Physical examination: Your doctor will perform a general exam on you by physically examining you, for example, by listening to your lungs and by examining your nose.
3. Lung function tests: These tests provide an objective method of confirming asthma diagnosis. They also help in assessing the severity of asthma and its response to treatment. The use of objective measures of lung function is particularly important because subjective measures, such as patient symptom reports and physicians’ physical examination findings, often do not correlate well with the variability and severity of airflow obstruction.
Lung function tests may be as simple as measuring peak flow with a peak flow meter, or may involve a series of spirometry tests by using a spirometer. A spirometer is used to evaluate the lung function most often in a hospital setting. On the other hand, a mini-peak flow meter is an inexpensive but useful device that you can use at home to assess your lung function by measuring peak expiratory flow rates and inform your physician about the level of control of the disease.
The results of your lung function tests are compared by your physician with expected values (test values that can be expected from other patients with similar physical traits like you). This helps your physician in knowing how severe the narrowing of the air passages is in you and also whether any ongoing treatment is adequate for you or not.
Remember: Measurement of lung function regularly, and especially when asthma is more active, is essential for planning correct treatment.
4. Laboratory tests: These tests may include X-ray of your chest and your sinus and skin tests for various allergies.
Once your exam and testing is finished, your physician will be able to determine whether you have asthma or another lung problem. If you do have asthma, you and your physician will work together to help you manage your asthma and keep you healthy and active.
How is Asthma diagnosis differentiated from other disease?
The symptoms of asthma can be found in association with other lung diseases such as bronchitis or emphysema. Therefore mere presence of these symptoms is not diagnostic of bronchial asthma. However, pattern of these symptoms is characteristic of asthma. The symptoms of asthma are usually intermittent and improve with therapy in asthma while in other lung diseases, the symptoms are usually present all the time and respond poorly to treatment.
An important characteristic of asthma symptoms is nighttime flare up. The night time flare of asthma is very common and can pose diagnostic problems. Usually people with night time symptoms are totally normal during the day. Hence there is no, or little, evidence of asthma at the routine time of examination. The situation can perplex both the patient and physician. In the morning, these patients get up early due to asthmatic distress. After taking a cup of morning tea the distress subsides gradually.