Diagnosing Asthma

Has your doctor diagnosed you with asthma? Getting a proper asthma diagnosis is the first step to self-managing this chronic lung disease. After diagnosing your asthma, the doctor can prescribe the most effective and safest asthma medications to treat your asthma symptoms so you can live an active and productive life.

Problems With Diagnosing Asthma

The problem with diagnosing asthma is most of the time patients do not have obvious asthma symptoms when they arrive at the doctor’s office. For instance, you may have coughed and wheezed for a week, and by the time you see your doctor, you have no symptoms at all. Then suddenly, when you least expect it, you might have asthma attack symptoms such as shortness of breath, coughing, and wheezing. Sometimes allergies to seasonal pollen or weather changes can trigger asthma attack symptoms. Other times, a viral infection such as cold or flu can trigger asthma attack symptoms. Smoking can worsen asthma symptoms, as can sinusitis or environmental allergies. Even exercise or sudden stress or allergies to aspirin or other medications can cause asthma attack symptoms.

If you have asthma, you may go for weeks to months without having any asthma symptoms. That makes diagnosing asthma even more difficult -- unless you do some homework, figure out your asthma triggers and causes of asthma, and help your doctor make an accurate asthma diagnosis. Once an accurate diagnosis is made, you can learn to recognize and treat your asthma symptoms with the right medications so you don’t have asthma symptoms that can interfere with your daily life.

Diagnosing Asthma and Your Doctor

Your doctor or asthma specialist plays the first and most significant role in helping you get control of your asthma. Not only does your doctor serve as the one who can accurately diagnose and prescribe treatment for your asthma, your doctor may become a close, dependable friend who can give you support when your concerns turn into ongoing worries and anxieties.

Not sure which type of doctor is right for you? See WebMD's Asthma Specialists.

At the initial exam, your doctor will obtain a detailed medical history, including any information on asthma symptoms, how you feel, known asthma and allergy triggers, your activity level and diet, your home and work environment, and family history. During this evaluation, it is important that you talk openly with your doctor about your asthma symptoms and triggers. Some questions you might consider beforehand include:


1. Can you describe your asthma symptoms?

(Check the following asthma signs and symptoms that apply to you)

____Shortness of breath

____Wheezing, possibly triggered by allergies, a cold, sinus infection, or bronchitis

____Frequent cough or just coughing at night

____Severe wheezing when breathing both in and out

____Rapid breathing

____Chest pain or pressure

____Difficulty talking

____Feelings of anxiety or panic

____Pale, sweaty face

____Blue lips or fingernails

2. When do you experience these asthma symptoms?

____ All the time; unpredictable

____ Only with exercise

____ At nighttime

____ Early morning hours while sleeping

___ During pollen season

___ When you feel stressed or anxious

___ When you smell smoke

___ When you smell fragrance

___ When you’re around dogs or cats

___ When you’re in air-conditioning or breathe cold air

___ When you laugh or sing

___ Associated with allergies, a sinus infection, or postnasal drip

___ Associated with heartburn or GERD

___ When you take aspirin, other anti-inflammatory drugs, or other medication

3. Do you have a family history of asthma or allergy?

4. Do you get bronchitis frequently?

5. Have you been diagnosed with asthma previously?

6. Have you been in the hospital emergency department for asthma or been on prednisone for asthma?

Diagnosing Asthma and Asthma Tests

After talking with you about your asthma symptoms and possible asthma triggers, your doctor will do a physical exam, laboratory testing, and other possible asthma tests. This will allow you to have a firm understanding of your breathing problems and will be the basis for the suggested plan of asthma treatment.

For more detail, see WebMD’s article Asthma Tests.

Your doctor may use one or more of the following asthma tests in diagnosing asthma. These tests are used to assess your breathing and to monitor the effectiveness of asthma treatment.

Spirometry -- a lung (or pulmonary) function test that measures how much air you can exhale. This asthma test confirms the presence of airway obstruction that improves with treatment, which is very characteristic of asthma, and can accurately measure the degree of lung function impairment. This test can also monitor your response to asthma medications and is recommended for adults and children over age 5.


For more information, see WebMD's Pulmonary Function Tests.

Peak Flow Testing -- a self-assessment you can do at home to evaluate lung function. The peak expiratory flow rate (PEFR) provides a reliable objective measure of airway function. Your doctor will go over how to use a peak flow meter, which involves taking a deep breath and blowing out as hard as you can. Peak flow is the highest airflow velocity that you can achieve. When done accurately, a drop in the peak flow measurement reflects an obstruction in your airways. While peak flow is less accurate than office spirometry for monitoring of lung function, peak flow monitoring at home can help you manage your symptoms at home and help indicate when an asthma attack may be approaching.

For more information, see WebMD’s Using a Peak Flow Meter.

Chest X-Ray -- while not routinely required, if there are symptoms that may be caused by another condition such as pneumonia, your doctor may want to do a chest X-ray. Or, if your asthma treatment is not working as well as it should, a chest X-ray may help to clarify the problem.

For more information, see WebMD's Asthma Tests.

Diagnosing Asthma Accurately

In diagnosing asthma, your doctor may order other asthma tests, including a methacholine challenge test. Methacholine is an agent that, when inhaled, causes airways to spasm and narrow if asthma is present. For more information, see WebMD's Pulmonary Function Tests.

Not everyone needs every asthma test. Trust your doctor to decide which set of asthma tests is best in your case to ensure no other medical problems are present. This can help you avoid extra testing that may add little to your diagnosis and only increases the number of tests and expense. If you still do not feel comfortable with the asthma diagnosis, talk to your doctor to see if more testing is necessary. Or, get a second opinion until you have peace of mind that the asthma or breathing problem has been diagnosed correctly. Then, proper asthma treatments can begin.

Getting back in control of your asthma depends on an accurate asthma diagnosis and asthma support. Once asthma is properly diagnosed, your doctor can prescribe the most effective asthma treatments, including an asthma inhaler and inhaled steroids that can relieve your breathing problems and help with prevention of asthma symptoms.


Be Ready to Ask Questions About Asthma

If you’re unsure what to ask your doctor at your appointment, we’ve provided some suggested questions for your visit with the asthma specialist.

For more information, see WebMD’s 10 Questions You Must Ask.

WebMD Medical Reference Reviewed by Carol DerSarkissian on February 28, 2018


Smolley, L. and Bruce, D. Breathe Right Now. (New York: Dell, 1998). 
Bruce, D. The Sinus Cure. (New York: Ballantine, 2007).
American Academy of Allergy, Asthma & Immunology: "Tips to Remember: asthma triggers and management;" "Allergic Conditions: Exercise-Induced Asthma (EIA);" and "An Unwelcome Return: 10 tips to ease your spring allergy symptoms."
Merck Manual Home Edition: "Asthma."

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