Asthma

Definition

Asthma is a chronic (long-term) condition that affects the airways in the lungs. The airways are tubes that carry air in and out of your lungs. If you have asthma, the airways can become inflamed and narrowed at times. This makes it harder for air to flow out of your airways when you breathe out.

Asthma is a chronic condition that affects 1 in 13 Americans. It affects people of all ages and often starts during childhood. Certain things can set off or worsen asthma symptoms, such as pollen, exercise, viral infections, or cold air. These are called asthma triggers. When symptoms get worse, it is called an asthma attack.

There is no cure for asthma, but treatment and an asthma action plan can help you manage it. The plan may include monitoring, avoiding triggers, and using medicines.

Black people in the United States have roughly a 40% higher risk of developing asthma than non-Hispanic white people in the U.S. Blacks are also five times more likely to visit the emergency room for symptoms. The severity of asthma also tends to be more severe for Blacks, making them three times more likely to die from an asthma episode than white people.

Causes

The exact cause of asthma is unknown, and the causes may be different from person to person. However, asthma often happens when the immune system strongly reacts to a substance in the lungs.

Normally, the body’s immune system helps fight infections. But it may also respond to other things you breathe in, such as pollen or mold. In some people, the immune system reacts strongly by creating inflammation.

When this happens, the airways swell, narrow, and may create more mucus. The muscles around the airways may also tighten. This can make it even harder to breathe. Over time, the airway walls can become thicker.

To understand asthma, it helps to understand how the lungs work.

Because the exact cause of asthma is unknown, you may not be able to prevent asthma in yourself or your children. You or your child may develop asthma when the body’s immune system is still developing.

Research suggests that you may be able to take some steps to help prevent asthma from developing. They include doing your best to keep your home free of dampness and mold, avoiding air pollution as much as possible, and making a healthy weight a priority for you and your children.

Asthma often starts during childhood when your immune system is still developing. Multiple factors may work together to cause it, such as:

• Things in the environment (called allergens) that affected you as a baby or young child, which may include cigarette smoke or certain germs
• Viral infections that affect breathing
• Family history, such as a parent who has asthma (especially your mother)

These can affect how your lung develops or how your body fights germs. Other things that may raise the risk of developing asthma include the following.

• Allergies: Asthma is usually a type of allergic reaction. People who have asthma often have other types of allergies, such as food or pollen.
• Obesity: This condition raises your chances of developing asthma or making your asthma symptoms worse.
• Race or ethnicity: African Americans and Puerto Ricans are at higher risk of asthma than people of other races or ethnicities are. African American and Hispanic children are more likely than non-Hispanic white Americans to die from asthma-related causes.
• Sex: More boys than girls have asthma as children, while asthma is more common among women in teens and adults.
• Occupational hazards: Breathing in chemicals or industrial dusts in the workplace can raise your risk of developing asthma.

Asthma triggers are things that set off or make asthma symptoms worse. Common triggers for asthma include:

• Indoor allergens, such as dust mites, mold, and pet dander or fur
• Outdoor allergens, such as pollens and mold
• Emotional stress, such as intense anger, crying, or laughing
• Physical activity, although with treatment, you or your child should still be able to be active
• Infections, such as colds, influenza (flu), or COVID-19
• Certain medicines, such as aspirin, which may cause serious breathing problems in people with severe asthma
• Poor air quality or very cold air

Symptoms

Symptoms of asthma may include:

• Chest tightness
• Coughing, especially at night or early morning
• Shortness of breath
• Wheezing, which is a whistling sound when you breathe out

Other conditions can cause these symptoms. But in asthma, the symptoms often follow a pattern:

• They come and go over time or within the same day.
• They start or get worse with viral infections, such as a cold.
• They are triggered by exercise, allergies, cold air, or breathing too fast from laughing or crying.
• They are worse at night or in the morning.

Diagnosis

Talk to your doctor if you or your child has asthma symptoms. Let them know if you know of anything that puts you at risk for asthma. You may need to see a team of healthcare providers, including your doctor, an asthma specialist, or an allergy specialist (called an allergist).

Get tips for talking to your healthcare provider and sample questions to ask at your next appointment.

You may need the following tests to figure out whether your symptoms are caused by asthma.

Spirometry

Spirometry is a type of lung function test that measures how much air you breathe out. It also measures how fast you can blow air out.

During the test, a technician will ask you to take a deep breath in. Then, you’ll blow as hard as you can into a tube connected to a small machine. The machine is called a spirometer. Your healthcare team may have you inhale, or breathe in, medicine that helps open your airways and then blow into the tube again. They can then compare your test results before and after taking the medicine. Some people feel lightheaded or tired from the required breathing effort.

Spirometry with bronchodilator tests

These tests measure how much and how fast air moves in and out both before and after you breathe in a medicine to relax the muscles in your airway.

Bronchoprovocation tests

These tests measure how your airways react when you breathe in specific substances in the air. During this test, you breathe in allergens or medicines that may tighten the muscles in your airways. How fast the air moves when you breathe in and out is measured before and after the test.

Peak expiratory flow (PEF) tests

PEF tests measure how fast you can blow air out using maximum effort. This test can be done during spirometry or with a small handheld device.

Fractional exhaled nitric oxide (FeNO) tests

Fractional exhaled nitric oxide (FeNO) tests measure how much nitric oxide is in your breath. High levels of nitric oxide may mean that the airways in your lungs are inflamed, which can make it hard to breathe.

For this test, you will breathe out into a tube that is connected to the portable device. It requires steady but not heavy breathing and has few or no risks. It is done in adults and children age 5 and older.

Allergy skin or blood tests

These tests can tell your doctor which allergens, such as pet dander or pollen, cause a reaction in your body when you are around these substances. Your doctor may do these tests if you have a history of allergies.

Treatments

Your provider will work with you to create a treatment plan, called an asthma action plan. Treatment usually depends on your age, how serious your asthma is, and how your body responds to the medicines.

Some people take daily medicines to control and prevent symptoms. But you can also carry medicines to use during an attack, such as a rescue inhaler. Your doctor may adjust your treatment until asthma symptoms are controlled. Watch our video to learn about treatment for asthma.

Quick-relief medicines

Quick-relief medicines help prevent or relieve symptoms during an asthma attack. They may be the only medicines needed for mild asthma or asthma that happens only with physical activity.

Your doctor will prescribe a quick-relief inhaler for you to carry at all times. Visit the Centers for Disease Control and Prevention (CDC) to learn how to use your asthma inhaler correctly.

Types of quick-relief medicines include:

• Inhaled short-acting beta2-agonists (SABAs) open the airways so air can flow through them during an asthma attack. Side effects can include tremors and rapid heartbeat.
• Oral corticosteroids reduce swelling in your airways caused by severe asthma symptoms.
• Short-acting anticholinergics help open the airways quickly. This medicine may be less effective than SABAs, but it is an option for people who may have side effects from SABAs.

Long-term control medicines

Your doctor may prescribe medicines to take daily to help prevent asthma attacks and control symptoms.

• Corticosteroids (steroid hormone medicines) reduce inflammation in the body. They may be taken as a pill or inhaled. The pill form can have more serious side effects than the inhaled form. Over time, high doses can raise your risk of cataracts (clouding of the eye) or osteoporosis. Osteoporosis makes your bones more likely to break. Common side effects from inhaled corticosteroids include a hoarse voice or a mouth infection called thrush.
• Biologic medicines may be prescribed for severe asthma. These include medicines such as benralizumab that are injected into a vein or below the skin.
• Leukotriene modifiers reduce swelling and keep your airways open. Your doctor may prescribe these pills alone or with steroid medicine.
• Inhaled mast cell stabilizers, such as cromolyn, help prevent swelling in your airways when you are around allergens or other asthma triggers.
• Inhaled long-acting bronchodilators, such as long-acting beta2-agonists (LABAs) or long-acting muscarinic antagonists (LAMAs), may be added to your inhaler to prevent your airways from narrowing.
• Allergy shots, called subcutaneous immunotherapy (SCIT), reduce the body’s response to allergens.

Bronchial thermoplasty

Bronchial thermoplasty may help if you have severe asthma and other treatments are not working. In this procedure, your doctor inserts a tube called a bronchoscope into your mouth. The bronchoscope has a camera at the end. Your doctor will guide the bronchoscope into your airways to see inside them. Your doctor will then apply heat to the muscles along the airways. This makes them thinner and helps prevent them from narrowing.

Create an asthma action plan

An asthma action plan is a written treatment plan that describes the following:

• How to identify allergens or irritants to avoid
• How to know if you are having an asthma attack and what to do
• Which medicines to take and when to take them
• When to call your doctor or go to the emergency room
• Who to contact in an emergency

Managing Asthma

To help you keep your asthma under control, you can:

• Look for training or support groups. Ask your doctor about asthma training or support groups to help you keep asthma under control.
• Educate yourself so you can understand the purpose of your medicines, how to prevent symptoms, how to recognize asthma attacks early, and when to seek medical attention.
• Monitor your airflow. As part of your asthma action plan, your doctor may show you how to control your asthma using a peak flow meter. Keep track of them in a record. You can compare your numbers over time to make sure your asthma is controlled. A low number can help warn you of an asthma attack even before you notice symptoms.
• Write down any problems with your asthma and bring the record with you to your doctor visit. This fact sheet includes a tool to help you track your symptoms and tips on measuring your peak flow.

Follow these steps to avoid triggers:

• Keep pets with fur out of your home or bedrooms if animal fur triggers asthma symptoms.
• Remove dust and mold from your house.
• Remove yourself from what is triggering your symptoms in the workplace. If you have occupational asthma, even low levels of allergens can trigger symptoms.
• Limit your time outdoors if allergen levels are high.
• Keep windows closed and avoid strenuous outdoor activity when air quality is low. For guidance, check the National Oceanic and Atmospheric Administration’s Air Quality Forecast Guidance. Thunderstorms can also affect air quality.
• Get the flu vaccine each year to help prevent the flu, which can raise the risk of an asthma attack. See below for information on COVID-19.
• Tell your doctor about all medicines you take, because aspirin and other medicines may cause serious breathing problems in people with severe asthma.
• Keep indoor cooking