Asthma is a chronic disease that affects the airways in your lungs. It causes the airways to become inflamed, swollen, and overly sensitive to certain triggers, making it harder for air to move in and out of the lungs.
During an asthma flare-up, the muscles surrounding the airways tighten, the lining of the airways swells, and extra mucus may be produced. Together, these changes narrow the airways and can make breathing difficult.
Asthma affects people of all ages. While some people develop asthma during childhood, others don't experience symptoms until adulthood. Although asthma cannot currently be cured, it can usually be managed successfully with medications, trigger avoidance, and an individualized treatment plan.
How Common Is Asthma?
Asthma is one of the most common chronic medical conditions worldwide. Millions of adults and children live with asthma, and many people are able to lead active, healthy lives with proper treatment. Good asthma control can reduce symptoms, prevent attacks, and lower the risk of emergency department visits and hospitalization.
What Happens During an Asthma Attack?
Normally, air flows freely through your airways. During an asthma attack, the muscles around the airways tighten (bronchospasm), the airway lining becomes inflamed and swollen, and thick mucus may narrow the airways even further. These changes reduce airflow, making it more difficult to breathe. Symptoms may develop gradually over several hours or come on suddenly. Our guide on what to do during an asthma attack covers the response step by step.
Common Symptoms of Asthma
Symptoms vary from person to person. Common signs include:
- Wheezing (a whistling sound while breathing)
- Shortness of breath
- Chest tightness or pressure
- Persistent coughing, especially at night or during exercise
- Difficulty taking a deep breath
- Fatigue due to poor sleep from nighttime symptoms
Some people experience symptoms only occasionally, while others have symptoms nearly every day. See our full guide to asthma symptoms and early warning signs.
What Causes Asthma?
The exact cause of asthma isn't fully understood, but it likely develops from a combination of genetic and environmental factors. Common triggers include seasonal allergies, dust mites, pet dander, mold, tobacco smoke, air pollution, respiratory infections, exercise, cold air, strong odors or fragrances, wildfire smoke, and emotional stress. Different people have different triggers, making personalized asthma management important — more in what causes asthma.
Who Is More Likely to Develop Asthma?
Risk factors include a family history of asthma, allergies or eczema, childhood respiratory infections, exposure to cigarette smoke, obesity, occupational exposure to chemicals or dust, and living in areas with significant air pollution. Having one or more risk factors does not guarantee someone will develop asthma.
Types of Asthma
Allergic asthma is triggered by allergens such as pollen, dust mites, mold, or pet dander. Exercise-induced bronchoconstriction produces symptoms during or shortly after exercise — see our exercise-induced asthma guide. Occupational asthma is caused by workplace exposures such as chemicals, dust, or fumes. Adult-onset asthma develops for the first time during adulthood. Severe asthma remains difficult to control despite appropriate treatment and may require additional medications such as biologic therapies.
How Is Asthma Diagnosed?
Your healthcare provider will review your symptoms, medical history, family history, possible triggers, and physical examination findings. Additional testing may include spirometry (measures how well your lungs move air in and out), peak flow monitoring (measures how quickly you can exhale), bronchodilator testing (evaluates whether breathing improves after using a rescue inhaler), and allergy testing. Sometimes additional testing is needed to rule out other conditions with similar symptoms.
How Is Asthma Treated?
Treatment depends on how often symptoms occur and how severe they are. Most asthma treatment involves two types of medications — explained in depth in Controller vs. Rescue Inhalers.
Rescue inhalers
Rescue inhalers provide rapid relief by relaxing the muscles around the airways. The most common rescue medication is albuterol. These medications work quickly but do not treat the underlying inflammation.
Controller medications
Controller medications reduce airway inflammation over time. These may include inhaled corticosteroids, combination inhalers, leukotriene modifiers, and biologic medications for severe asthma. Controller medications are taken regularly, even when you're feeling well.
Lifestyle Changes That Can Help
In addition to medications, many people benefit from avoiding known triggers, not smoking, staying physically active, receiving recommended vaccinations, treating seasonal allergies, maintaining a healthy weight, following an asthma action plan, and learning proper inhaler technique. Good inhaler technique is one of the most important—and most overlooked—parts of asthma treatment.
Can You Exercise if You Have Asthma?
Yes. Many people with asthma participate in sports at every level, including elite competition. If exercise triggers your symptoms, your healthcare provider may recommend using a rescue inhaler before activity or adjusting your treatment plan. Well-controlled asthma should not prevent most people from staying active.
Frequently Asked Questions
Is asthma curable?
No. Asthma is a chronic condition, but most people can successfully control their symptoms with proper treatment.
Is asthma contagious?
No. You cannot catch asthma from another person.
Can asthma develop later in life?
Yes. Although asthma often begins during childhood, many people develop asthma as adults.
Can allergies cause asthma?
Allergies don't directly cause asthma, but they are a common trigger for asthma symptoms in many people.
Can asthma go away?
Some children experience fewer symptoms as they grow older. However, asthma can return later in life, and adults generally require ongoing management.
When Should You Contact Your Healthcare Provider?
Schedule an appointment if you're wheezing frequently, you have a cough lasting several weeks, you're using your rescue inhaler more than recommended, your symptoms wake you up at night, exercise consistently causes breathing problems, or your asthma symptoms are becoming more frequent. Your treatment plan may need adjustment.
Seek Immediate Medical Care If
Call 911 or seek emergency medical care immediately if you experience:
- Severe shortness of breath
- Difficulty speaking in full sentences
- Lips or fingernails turning blue or gray
- Rapid worsening despite using your rescue inhaler
- Chest pulling inward with each breath
- Confusion or difficulty staying awake
These symptoms may indicate a life-threatening asthma attack.
The Bottom Line
Asthma is a common chronic lung condition that causes inflammation and narrowing of the airways, leading to symptoms such as wheezing, coughing, chest tightness, and shortness of breath. While there is no cure, modern treatments allow most people to keep asthma well controlled and maintain an active lifestyle.
Understanding your triggers, using your inhalers correctly, and following an asthma action plan are the keys to preventing asthma attacks and protecting your long-term lung health. If your symptoms are becoming more frequent or your rescue inhaler isn't providing adequate relief, schedule an appointment with your healthcare provider to review your treatment plan.