Asthma

Asthma                           

 Is a condition in which your airways narrow and swell and may produce extra mucus. 

This can make breathing difficult and trigger coughing, a whistling sound (wheezing) when you breathe out and shortness of breath.

For some people, asthma is a minor nuisance. For others, it can be a major problem that interferes with daily activities and may lead to a life-threatening asthma attack.

Asthma can't be cured, but its symptoms can be controlled.

Symptoms:

Asthma symptoms vary from person to person. You may have infrequent asthma attacks, have symptoms only at certain times — such as when exercising — or have symptoms all the time.

Asthma signs and symptoms include:

• Shortness of breath

• Chest tightness or pain

• Wheezing when exhaling, which is a common sign of asthma in children

• Trouble sleeping caused by shortness of breath, coughing or wheezing

• Coughing or wheezing attacks that are worsened by a respiratory virus, such as a cold or the flu

Signs that asthma is probably worsening include:

• Asthma signs and symptoms that are more frequent and bothersome

• Increasing difficulty breathing, as measured with a device used to check how well your lungs are working (peak flow meter)

• The need to use a quick-relief inhaler more often

For some people, asthma signs and symptoms flare up in certain situations:

• Exercise-induced asthma, which may be worse when the air is cold and dry

• Allergy-induced asthma, triggered by airborne substances, such as pollen, mold spores, cockroach waste, or particles of skin and dried saliva shed by pets (pet dander)

Asthma attack

If you have asthma, the inside walls of the airways in your lungs can become inflamed and swollen. In addition, membranes in your airway linings may secrete excess mucus. The result is an asthma attack. During an asthma attack, your narrowed airways make it harder to breathe, and you may cough and wheeze.

Diagnosis

Physical exam

Your doctor will perform a physical exam to rule out other possible conditions, such as a respiratory infection or chronic obstructive pulmonary disease (COPD). Your doctor will also ask you questions about your signs and symptoms and about any other health problems.

Tests to measure lung function

You may be given lung function tests to determine how much air moves in and out as you breathe. These tests may include:

Spirometry. This test estimates the narrowing of your bronchial tubes by checking how much air you can exhale after a deep breath and how fast you can breathe out.

Peak flow. A peak flow meter is a simple device that measures how hard you can breathe out. Lower than usual peak flow readings are a sign that your lungs may not be working as well and that your asthma may be getting worse. Your doctor will give you instructions on how to track and deal with low peak flow readings.

Lung function tests often are done before and after taking a medication to open your airways called a bronchodilator (brong-koh-DIE-lay-tur), such as albuterol. If your lung function improves with use of a bronchodilator, it's likely you have asthma.

Additional tests

Other tests to diagnose asthma include:

Methacholine challenge. Methacholine is a known asthma trigger. When inhaled, it will cause your airways to narrow slightly. If you react to the methacholine, you likely have asthma. This test may be used even if your initial lung function test is normal.

Imaging tests. A chest X-ray can help identify any structural abnormalities or diseases (such as infection) that can cause or aggravate breathing problems.

Allergy testing. Allergy tests can be performed by a skin test or blood test. They tell you if you're allergic to pets, dust, mold or pollen. If allergy triggers are identified, your doctor may recommend allergy shots.

Nitric oxide test. This test measures the amount of the gas nitric oxide in your breath. When your airways are inflamed — a sign of asthma — you may have higher than normal nitric oxide levels. This test isn't widely available.

Sputum eosinophils. This test looks for certain white blood cells (eosinophils) in the mixture of saliva and mucus (sputum) you discharge during coughing. Eosinophils are present when symptoms develop and become visible when stained with a rose-colored dye.

Provocative testing for exercise and cold-induced asthma. In these tests, your doctor measures your airway obstruction before and after you perform vigorous physical activity or take several breaths of cold air.

How asthma is classified:

To classify asthma severity, the doctor will consider how often the patient has signs and symptoms and how severe they are. The doctor will also consider the results of the physical exam and diagnostic tests.

Determining asthma severity helps doctor choose the best treatment. Asthma severity often changes over time, requiring treatment adjustments.