What is Asthma?


Asthma is a long-term lung disease that causes episodes of coughing, wheezing, chest tightness and shortness of breath. Symptoms can be mild or severe, and sometimes life-threatening. Like all chronic illnesses, asthma cannot be cured, but in most cases, asthma is very manageable.

What causes asthma?

Anyone of any age, family background, race, sex or general health can develop asthma. Researchers think many genetic & environmental factors play a role, especially during the first years of life when the immune system is developing.

  • Family history of asthma or allergies
  • Mother’s smoking or exposure to secondhand smoke or air pollution during pregnancy
  • Early childhood exposure to secondhand smoke, air pollution or indoor allergens such as dust mites, cockroaches or mold
  • Damage to developing lungs due to premature birth or early childhood respiratory illnesses
  • For adults, exposure to chemical irritants or industrial dust in the workplace

Ad for Cinqair learn more

How does asthma affect the lungs and airways?

The airways inside your lungs look like an upside-down tree. The respiratory system is in the chest and is made up of several different parts:

  • Upper respiratory system – This is the nose, sinuses, and the parts of the airway called the pharynx and the part of the larynx above the vocal chords.
  • Lower respiratory system – This is the portion of the larynx below the vocal chords, the trachea, bronchi and bronchioles (all breathing tubes that get smaller and smaller – especially in the lower lungs)
illustration of the human lungs

It’s important to understand that asthma is a syndrome and not just a single disease. Asthma affects the lungs in two ways:

Airway inflammation

Asthma begins with inflammation: The lining of the airways – the breathing tubes leading into the lungs – becomes swollen, inflamed and clogged with mucus and fluid.

Asthma inflammation is the quiet part of asthma. When we talk about quiet asthma, that’s when the inflammation and swelling takes place. You can’t feel or see what’s going on, but each time your airways are exposed to your asthma triggers, the inflammation increases and your symptoms are likely to get worse.

Illustration of a Bronchospasm


Muscles surrounding the airways tighten and contract as they try to keep the passageways open. Inhaled allergens or irritants like secondhand smoke and air pollution act like sandpaper on the raw surfaces. You begin to cough and wheeze as you struggle to breathe. This is called bronchospasm.

Bronchospam is the noisy part of asthma. Noisy asthma occurs when your airways are so inflamed they’re very sensitive. Exposure to the slightest irritation or allergen triggers bronchospasm – the twitching and sudden constriction of your airways creating the coughing, wheezing and shortness of breath that you can hear.

Image of trusted messengers logo in white

Free COVID-19, asthma, COPD screenings and digital health support  >>

What is an asthma attack?

If your asthma symptoms are worsening you could be having an asthma attack, also known as an asthma flare, asthma exacerbation, or asthma episode. Any of these signs indicate the need for immediate medical treatment; follow your Asthma Action Plan. Call 911 if you’re not sure.

An asthma attack occurs when an asthma trigger causes the lungs to become inflamed and swollen. The muscles around the breathing tubes tighten or spasm and more mucus than usual is produced. All of these work to make the breathing tubes more narrow and make it harder to get air into the lungs.

Photo of Black Girl Young African American Woman Under Panic Attack

How do you stop an asthma attack?

Asthma episodes can be mild or severe. You need to follow your Asthma Action Plan. An asthma action plan is a treatment plan from the doctor will help provide guidance on what to do when it’s hard to breathe. It outlines the medications to use and how to limit your activity if needed. Learn more about asthma symptoms, triggers and treatment so you can prevent asthma attacks and learn how to treat an asthma attack if you do have one.

It is important to understand what triggers your asthma symptoms. Asthma is not a one-size-fits-all disease – what sets off symptoms for you or someone in your family may be quite different from what affects others. When you understand what’s happening inside your lungs and how they respond to allergens and irritants like pollen, dust mites or smoke, you can take steps to prevent or minimize symptoms.

What are common asthma symptoms?

Common asthma symptoms include:

Coughing: Coughing from asthma is often worse at night or early morning. Sometimes it’s your only symptom. It can be dry or mucus filled.

Wheezing: This is a whistling or squeaky sound especially when you breathe out. Sometimes wheezing can be heard easily; other times you need a stethoscope. A stethoscope is a medical device used to listen to breath sounds.

Chest tightness: This can feel like something is squeezing or sitting on your chest.

Shortness of breath: You may feel breathless, like you can’t catch your breath or breathe deeply enough. You may feel as though you are out of shape and constantly tired.

What is an Asthma Action Plan?

An asthma action plan is a written personal plan of treatment. If you don’t have one, make an appointment with your doctor to develop one as soon as possible.

An Asthma Action Plan should spell out:

  • how to treat your asthma daily
  • what to do when symptoms get worse
  • how to handle situations such as exercise or when you have a cold or virus.
Asthma Action Plan downloadable form and instruction bookoadable Form &

Your Asthma Action Plan will change as your asthma improves or worsens. You review the plan with your doctor at every appointment, including follow-up visits following an asthma attack as well as when your asthma is under control. The Asthma Action Plan is usually divided into three areas – like a stoplight:

  • Green – For every day, even when feeling well
  • Yellow – When there is a cough, wheeze, shortness of breath or chest tightness
  • Red – When breathing is hard and fast, ribs are sticking out, having trouble talking, walking or sleeping
Understanding Asthma magazine mockup with Asthma Action Plan form on the open page

Get a Free Copy of Our "Understanding Asthma" Guide ➤

Frequently Asked Asthma Questions

How is asthma diagnosed?

It is often not easy for a doctor to make a diagnosis of asthma, as symptoms often come and go. That’s why you should always talk with a doctor – preferably a board-certified allergist or pulmonologist – who is familiar with asthma diagnosis and treatment guidelines.

Your doctor will act like a skilled detective to combine the following information to determine whether asthma or some other cause is responsible for your symptoms:

  • Your family and symptom history
  • Physical exam
  • Medical tests

How is asthma treated?

Asthma medications play a central role in a treatment plan. Some medications prevent or reduce airway inflammation; others interrupt the allergic reaction that triggers symptoms; others relieve coughing and wheezing, making it easier to breathe.

Your doctor will work with you to find the right combination of medicines to manage your asthma and adjust the type and amount based on your symptoms. The goal of asthma treatment is to have you feel your best with the least amount of medicine.

What if I can’t afford asthma medication?

Asthma inhalers and other types of respiratory medications vary in price. Some are less costly, and some are very expensive. If you cannot afford the cost of your asthma inhaler or other respiratory medication you can:

  • Shop around. Compare prices at other pharmacies or check prices at GoodRx. 
  • Contact the manufacturer for patient assistance programs. 
  • Ask your doctor to prescribe an alternative. Sometimes less costly alternatives are available.

If you are still unable to afford the prescribed medication, talk with your doctor. It’s very important to use your medication as prescribed. Be sure to ask your doctor for help you so you don’t go without taking your asthma medication or other respiratory medication.

What is severe asthma?

Severe asthma is asthma that, despite all that you do:

  • requires high-dose inhaled corticosteroids plus long-acting beta2-agonists and/or additional controller medication or
  • requires oral corticosteroids to prevent it from becoming uncontrolled or remains uncontrolled despite therapy.

People with severe asthma often experience high rates of emergency department visits, hospitalizations and school or work absenteeism.  They often find themselves unable to perform simple activities of daily living.

Once considered a single, though complex disease, asthma is now recognized as a syndrome or spectrum of diseases with environmental and genetic factors that cause airway inflammation and bronchospasm – leading to coughing, wheezing and shortness of breath. 

It’s estimated that 5-10 percent of people with asthma have severe asthma. However, the percentage may be higher because additional studies reveal about 50 percent of asthma patients have poorly controlled symptoms despite treatment.

Learn about eosinophilic asthma, a subtype of asthma that is often severe — visit eosasthma.org” and link to eosasthma.org

How do I know if my asthma is controlled?

Sometimes you can experience asthma symptoms on a regular basis even when following your treatment plan. This means that your asthma may not be in control. There are tools to use to use to assess whether your asthma is in control, and when to see an asthma specialist.

Asthma in babies and children

As many as 80% of children that will have asthma develop symptoms before the age of 5. We don’t always know why a child develops asthma, but some causes can be:

  • Family history of asthma, allergies or eczema (atopic dermatitis)
  • Premature birth
  • A viral infection (such as respiratory syncytial virus, or RSV), especially when the baby is less than 6 months old 
  • A mother who smokes during pregnancy

Learn more about the symptoms of asthma in babies, toddlers and children; how asthma is diagnosed and treated in babies, toddlers and children and whether children can outgrow their asthma.

Asthma - vaping and smoking

Learn more about the effects of smoking, vaping, juuling and e-cigarettes on the lungs with asthma; the effects of secondhand smoke with asthma and what you should do to avoid smoke and smoking as a trigger with asthma.

What is exercise-induced asthma?

About one in 10 people experience asthma-related coughing or shortness of breath during or shortly after physical activity. 

In exercise-induced asthma (also called exercise-induced bronchospasm, or EIB), airway muscle spasms constrict air flow and cause shortness of breath, coughing, wheezing, chest tightness and fatigue. Symptoms usually appear 5-10 minutes after exercise starts or ends.

If you think you have EIB, make an appointment with a doctor who will take your medical history and have you perform breathing tests after exercise and while resting and give you a treatment plan to manage your EIB.

How does asthma affect pregnancy?

Asthma — one of the most common health complications of pregnancy — presents special challenges.

There is no way to predict how pregnancy will affect your asthma symptoms. Some expectant mothers find that asthma symptoms improve during pregnancy; others say they worsen or remain the same. 

As pregnancy progresses, there is less room inside your body to take a full, deep breath. Normal activities such as climbing stairs may leave you short of breath, but they should not make you cough, wheeze or experience reduced breathing levels. (Use a handheld peak flow meter to check.)

Learn the difference between breathing changes due to pregnancy and symptoms of asthma. If breathing symptoms improve after using your bronchodilator inhaler, symptoms are most likely due to asthma and should be reported immediately to your obstetrician, allergist or other healthcare professional. Also learn more about the risks involved in being pregnant and having asthma; the safety concerns you may have about asthma medications during pregnancy, as well as in labor and delivery, and the use of natural remedies for asthma.

Is asthma contagious?

Diseases are typically communicable (or contagious) or non-communicable. Contagious respiratory diseases include the common cold, influenza, or COVID-19. Contagious diseases are normally caused by some sort of bacteria or virus. But asthma is not a contagious respiratory disease. So, you can’t catch asthma or give asthma to someone else. Asthma can be hereditary or caused by environmental factors. If a bunch of people living in the same building develop asthma, you may think it is contagious. Rather, it is likely that there are things in the building causing people to get sick. Exposure to dust mites, mold, cockroaches, and pollutants are risk factors for developing asthma. Several people in the same family may also develop asthma. That may be due to genetics, environmental exposures, or both.

Are there other conditions that may look like asthma or complicate asthma?

There are other types of respiratory conditions that are different than asthma.  The symptoms, diagnosis and treatment can vary depending upon the condition. Here are some of them.