What is Severe Asthma?
Severe asthma is a type of asthma that is hard to control. Symptoms may occur most days and most nights. Severe asthma can involve constant or frequent inflammation in your airways. Unlike mild asthma, severe asthma doesn’t get better easily with treatment. Symptoms persist – coughing, wheezing, chest tightness and shortness of breath.
People with severe asthma have high rates of emergency department visits and hospitalizations. They also have high rates of school or work absenteeism. They may be unable to perform simple activities of daily living due to their lung disease.
Asthma guidelines in the United States and around the world define severe asthma as when…
- a person needs high-dose treatment to keep it under control.
- symptoms are still bad or happen often, even with high-dose treatment.
High-dose medications include inhaled corticosteroids (ICS, which help reduce inflammation) and long-acting beta2-agonists (LABAs, which relax muscles around the airways). If these medications are not working, then it may be time to ask your doctor about different asthma treatment options.

Other people with asthma people may rely too much on oral corticosteroids (OCS) to control symptoms. But OCS is not meant for long-term therapy. This can lead to severe side effects.
More advanced medications are now available to treat severe asthma. Biologics are prescribed for severe asthma. These are injections or infusions. Biologics address asthma at the cell level. They can help stop inflammation before it can start.
What can you do if your asthma is severe, frequent, and not getting better? First, speak with an asthma specialist – a board-certified allergist or a pulmonologist. These doctors can work with you to develop an effective treatment plan.
How common is severe asthma?
It’s estimated that between 5-10% of people with asthma have severe asthma. In children, severe asthma affects 6% of 12-17 year olds and 2% of 6-11 year olds.
It is believed the rates may be higher. Some people with uncontrolled asthma may not see a doctor often enough. They may not fully report their symptoms. Studies show about half of adult asthma patients and 18% of children have poorly controlled symptoms despite treatment.
What are severe asthma symptoms?
The common symptoms of asthma are coughing, wheezing, chest tightness and shortness of breath. Some people may also experience fatigue, difficulty sleeping, and excess mucus.
Severe asthma symptoms are more intense and frequent than those of mild or moderate asthma. The coughing and wheezing may persist, especially at night. These symptoms may not improve with standard ICS or LABA treatments and they often interfere with daily life.
People with severe asthma may have repeat flare-ups that require emergency medical treatment. The flare-ups may happen even when using a quick-relief inhaler and taking controller medications correctly. They may need oral corticosteroids to calm symptoms.
During a severe asthma attack, some people may show signs of low oxygen levels. The signs include blue lips or fingernails (called cyanosis). This is a medical emergency. Use a quick-relief inhaler, call 9-1-1 for emergency medical treatment, and go to the nearest hospital or emergency department.
Is there a difference between severe asthma and uncontrolled asthma?
Yes. Severe asthma can be controlled or uncontrolled. Likewise, uncontrolled asthma is not always classified as severe. Anyone with asthma can have uncontrolled symptoms.
You can check your asthma control using the Rules of Two®. If you answer yes to any of the following, your asthma may be uncontrolled and you should see a doctor as soon as possible:
Rules of Two |
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Rules of TWO® When is quick relief for asthma NOT ENOUGH? DO YOU…. ![]() ✓ Take your quick relief inhaler more than TWO TIMES A WEEK? ✓ Awaken at night with asthma more than TWO TIMES A MONTH? ✓ Do you refill your quick-relief inhaler more than TWO TIMES A YEAR? ✓ Use prednisone TWO or more times a year for flares of asthma? Measure changes in peak flow with asthma symptoms of more than TWO TIMES 10 (20%)? If you answer “yes” to any of them, talk to your doctor. Rules of Two is a registered trademark of Baylor Health Care System |
Some people with severe asthma may have symptoms under control. Others may struggle with symptoms even on high doses of daily controller medications. These symptoms may be frequent throughout the day and night. The level of asthma severity involves:
- How often you need your quick-relief rescue medication.
- The frequency and duration of your daytime and nighttime asthma symptoms.
- The impact of asthma on your daily life. Think about the limitations to activities of daily living or ability to exercise.
Intermittent Asthma | Mild Persistent Asthma | Moderate Persistent Asthma | Severe Persistent Asthma | |
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Daytime Symptoms | Less than 3 times a week | 3-6 times a week | Every day | Continuously throughout the day |
Nighttime Symptoms | Less than 2 times a month | 3-4 times a month | 5 or more times a month but not every night | Every night |
Use of Quick-Relief Medication | Less than 3 times a week for asthma symptoms | More than 2 days a week, but not daily | Daily | Several times a day |
Limitations | No limitations to activities of daily living or exercise | Minor limitations to activities of daily living or exercise | Increased limitations to activities of daily living or exercise (more than 2 times per week) | Extreme limitations to activities of daily living or exercise |
Be sure to monitor your severe uncontrolled asthma symptoms. Are chest tightness and breathlessness increasing? Is your cough and wheezing getting worse? See your doctor or asthma specialist promptly. You could be at risk for severe asthma or an asthma attack.
What are the different types of severe asthma?
Each person’s asthma is unique. Doctors diagnose it on a spectrum. Severe asthma typically involves symptoms throughout the day and most nights per week. Patients may need to go to the emergency department or hospital often. They may be unable to go to work or school, or do simple activities, due to breathing problems.
Phenotypes (or subtypes) of asthma include allergic asthma and nonallergic asthma. Allergic asthma involves symptoms that are triggered by exposure to allergens like pollen, mold, dust mites or pet dander. Nonallergic asthma involves symptoms caused by air pollution, exercise, tobacco smoke, viruses and strong smells. It is often more associated with adult-onset asthma. Allergic asthma and non-allergic asthma can worsen severe asthma symptoms.
Others have a subtype called eosinophilic asthma. This is usually a severe form of asthma. High levels of eosinophils – a type of white blood cell – in the body can lead to severe asthma or cause an asthma attack. Eosinophilic asthma often involves Type 2 inflammation.
Another severe asthma subtype is neutrophilic asthma. It involves neutrophils, a type of white blood cell that is designed to fight infection. The condition is often more resistant to corticosteroid treatment and involves hard-to-control inflammation not related to Type 2.
Why does the type of severe asthma you have matter? Different types of asthma may need different kinds of treatment. For example, certain biologic medications are prescribed for allergic asthma. Other biologics are prescribed to treat eosinophilic asthma.

How is severe asthma diagnosed?
Doctors diagnose severe asthma by checking how the disease affects a person. This is called a clinical assessment. The goal is to confirm that asthma is truly severe.
To diagnose severe asthma, your doctor will…
- Check your medical history.
- Review your signs and symptoms.
- Perform a physical exam.
- Conduct lung function tests, such as spirometry or FeNO, to identify your level of asthma severity. Spirometry measures your forced expiratory volume (FEV1). It evaluates how much air you can exhale in one second during a forced breath.
- Consider what asthma medication you take and evaluate whether it’s working.
- Order blood tests.
Diagnosis of eosinophilic asthma may also involve blood tests, a sputum sample, or a bronchial biopsy of fluid examination.
Severe asthma can also be diagnosed by ruling out factors that make asthma harder to control. These factors may include:
- incorrect inhaler technique;
- frequent exposure to environmental triggers (pollen, mold, pet dander, cockroaches or mice);
- lack of access to affordable medical care or treatment
- poor medication adherence;
- poor stress management
- other health conditions, such as COPD.
If you think you have severe asthma, or your asthma is worsening, speak with a specialist. Get a referral from your primary care doctor to see a board-certified allergist or pulmonologist. Ask for an assessment of your symptoms. Find out if your asthma medication is working.
There are several asthma assessment tools you can use to determine if your asthma is in control or not:
What is the Asthma Control Test?
For people with severe asthma, staying ahead of symptoms is critical. The Asthma Control Test (ACT) is a 5-question test. It helps patients and doctors measure asthma control over the last four weeks. It can help determine if any treatment adjustments are needed. The ACT asks about symptoms, activity limitations, nighttime awakenings, and how often quick-relief inhalers are needed.
Each question is scored from 1 (worst) to 5 (best), for a total score ranging from 5 to 25:
- 20–25: Asthma is well-controlled.
- 16–19: Asthma is somewhat controlled.
- 15 or below: Asthma is poorly controlled, and medical attention is needed.
A similar test is the Asthma Impairment and Risk Questionnaire (AirQ). This is a 10-question test of “yes” or “no” answers. It is for adults and children ages 12 and older. The AirQ can help determine if asthma is well-controlled, not well-controlled or very poorly controlled. It asks about your asthma medications and symptoms. The total number of “yes” responses is your AirQ score.
The ACT and AirQ are not intended to diagnose severe asthma. They do not take the place of what your primary care doctor or asthma specialist recommends for severe asthma treatment. Use these tests to determine your level of asthma control at any given time. Then talk with your doctor or asthma specialist about whether you need to adjust your medication or treatment plan.
How is severe asthma treated?
Treatment for severe asthma focuses on controlling inflammation and reducing symptoms. It also aims to reduce the risk of asthma attacks and improve quality of life. Severe asthma doesn’t always respond well to standard treatments. So doctors may use a combination of therapies tailored to the patient’s needs.
Most people with asthma are prescribed a quick-relief albuterol inhaler. These short-acting beta2-agonists (SABA) work by relaxing the airway muscles and treating symptom flare-ups. A quick-relief inhaler called AIRSUPRA® can benefit severe asthma patients. It combines albuterol with an inhaled corticosteroid. This approach provides the quick relief of symptoms while also working to calm the inflamed airways in the short and long term. Asthma guidelines support the use of AIRSUPRA for moderate to severe asthma.
Your doctor may prescribe a long-acting beta2-agonist and inhaled corticosteroid for long-term asthma control. LABAs relax the muscles around the airways. ICS works to reduce inflammation in the airways. Severe asthma is sometimes the diagnosis when LABA and ICS are not effective. Doctors then turn to different medications, or a combination of medications, for better control.
One asthma therapy combines a LABA and ICS. It’s called SMART therapy, for Single Maintenance and Reliever Therapy. (It’s sometimes called MART therapy.) This combo allows a patient with moderate to severe asthma to use one inhaler for both quick relief and maintenance therapy. It’s available in two medications:
- budesonide/formoterol (Symbicort®)
- mometasone/formoterol (Dulera®)
Budesonide and mometasone are inhaled corticosteroids. Formoterol is a LABA. SMART therapy can be prescribed to adults and children ages 5 and older with severe asthma. It is considered an easier treatment plan to follow because it involves just one device.
Biologics
Biologics are injectable medications. They target cells, pathways and proteins that cause inflammation in the body. Biologics focus on treating the source of symptoms at the cell level rather than the symptoms themselves.
Biologics are typically prescribed as an add-on therapy for severe asthma. This means you continue to take a daily controller medication in addition to the biologic.
Biologics are usually administered as an injection every 2 to 8 weeks. (One biologic is available as an infusion.) They are intended to help patients gain long-term asthma control. They help improve asthma by reducing inflammation and the risk of an asthma attack.
What are different types of biologics for asthma?
- Anti-IgE biologics work to interrupt a protein (antibody) called IgE. This antibody is part of the allergic response to an allergen and the start of the inflammatory process. The medication in this category is omalizumab.
- Eosinophil biologics decrease eosinophils (a white blood cell) in the body that promote inflammation. These medications include benralizumab, dupilumab, mepolizumab and reslizumab.
- TSLP (thymic stromal lymphopoietin) blockers work by blocking cytokines from starting airway inflammation. The medication in this category is tezepelumab-ekko.
Oral corticosteroids (OCS)
Oral corticosteroids are prescribed to treat acute asthma flares. They are sometimes referred to as oral steroids. OCS is usually given only for short periods of time (5-7 days) – called a burst. The pill gradually reduces asthma symptoms and opens up the airways.
Some people with severe asthma may rely too much on OCS to control symptoms. OCS is not meant for long-term therapy or for use more than two times per year. The dosage of an oral corticosteroid is 10 times the dose of an inhaled corticosteroid. As a result, there is an increased risk of side effects, especially if OCS is taken long-term. These side effects may include weight gain, high blood sugar, eye problems, thinning bones, mood swings and depression. Talk with your doctor about the risks vs. benefits of long-term oral corticosteroid use.
Leukotriene modifiers
These are pills that help block chemicals in the body called leukotrienes. When activated, leukotrienes can cause inflammation and tightening of the airways. Montelukast (Singulair®) is a leukotriene modifier prescribed for people with asthma. It is important to note the montelukast drug package contains a boxed warning for mental health side effects. These side effect may include anxiety, sleep disorder, depression, and behavior and mood-related changes. Discuss the risks of side effects with your physician.
Long-acting muscarinic antagonists (LAMA)
These are also called anticholinergic medications. LAMAs work by blocking a neurotransmitter called acetylcholine. This is a chemical messenger that plays a role in causing bronchoconstriction of the airways. LAMAs are primarily prescribed to treat COPD, but one – tiotropium bromide (Spiriva® Respimat®) – is approved for severe asthma. They are typically used in combination with LABAs or ICS to treat severe asthma.
Phosphodiesterase-4 (PDE-4) inhibitors
PDE-4 inhibitors, primarily roflumilast (Daliresp®), offer a novel treatment option for severe asthma with chronic inflammation that is not well controlled by traditional therapies. PDE-4 is an enzyme that plays a key role in regulating levels of inflammatory cells like eosinophils and neutrophils. They can help reduce airway inflammation, limit immune cell activation, and decrease the frequency of asthma attacks. Their use is generally limited to more difficult-to-treat cases.
Treatments for Severe Asthma Phenotypes
Once considered a single disease, asthma is now recognized as a spectrum of diseases. Severe asthma is one form of the disease. It has many subtypes that respond to targeted treatments and medications. These subtypes include allergic, non-allergic, and eosinophilic asthma.
Asthma Phenotype | Characterized by difficult-to-treat asthma plus: | Targeted Treatment |
---|---|---|
Allergic asthma (IgE) | Total serum IgE level = 30-700 IU/ml with demonstrated IgE-mediated hypersensitivity to a perennial allergen. | Add anti-IgE biologic (omalizumab) |
Eosinophilic | Blood eosinophils above 300 cells/uL with either 2 or more asthma attacks requiring OCS in past year; or blood eosinophils above 150 cells/uL with 3 or more asthma attacks requiring OCS in past year. | Add anti-IL5 biologic (mepolizumab, reslizumab, benralizumab) or anti-IL4/IL13 biologic (dupilumab). |
Nonallergic asthma | Symptoms not caused by allergens or high levels of eosinophils; instead, symptoms are triggered by environmental irritants such as air pollution, viruses, or exercise-induced asthma. | Add anti-thymic stromal lymphopoietin (TSLP) biologic (tezelepumab-ekko) |
Neutrophilic asthma | Patient who doesn’t qualify for other targeted therapies and/or has tried and failed targeted therapies for which s/he might be eligible and demonstration of variable airflow obstruction by bronchodilator reversibility | Add a macrolide antibiotic or a phosphodiesterase-4 (PDE-4) inhibitor |
Note: tezelepumab-ekko can also treat allergic asthma and eosinophilic asthma.
What is bronchial thermoplasty for severe asthma?
Bronchial thermoplasty is an outpatient surgical procedure. It is for adults ages 18 and older with severe persistent asthma symptoms despite using standard therapy. The procedure is performed in three outpatient visits under moderate or general anesthesia.
A pulmonologist or other qualified physician inserts a long, slender tube called a bronchoscope through the mouth and into the lungs and surrounding airways. It heats and shrinks the size of muscle tissue. This allows more air to pass through and make breathing easier. Potential side effects may include a short-term worsening of asthma symptoms. These side effects usually resolve within a week.
If you have severe and difficult-to-control asthma, ask your doctor if bronchial thermoplasty is right for you. And be sure to check your health insurance to confirm if the procedure is covered.
How can I keep severe asthma under control?
If your asthma is persistent, severe, and not getting better on your current medications, speak with your doctor, preferably an asthma specialist. These doctors can work with you to develop a more effective treatment plan.
Here are some additional steps you can take to help control severe asthma:
- Work closely with your doctor to create and follow an Asthma Action Plan.
- Take medications as prescribed, even when symptoms feel under control. If you take biologics, don’t miss a scheduled dose.
- Monitor symptoms regularly using tools like the Asthma Control Test.
- Identify and avoid triggers like allergens, smoke, and pollution.
- Address coexisting conditions, such as allergies or acid reflux, that can worsen asthma.
What is Type 2 inflammation for asthma?
Type 2 inflammation is an overactive immune system response. It plays a major role in chronic diseases such as asthma, allergies, eczema, and more. Type 2 inflammation and asthma involves high levels of IgE antibodies and/or white blood cells called eosinophils. This can lead to excess inflammation in the airways for people with asthma.
People with asthma who have Type 2 inflammation often have severe asthma or eosinophilic asthma.
Biologic medications are often recommended for people with Type 2 inflammation. These medications work by blocking the activity of IgE or the molecules that activate eosinophils. By targeting the immune response at the cellular level, biologics help prevent inflammation. This can lead to better symptom control.
How can immunotherapy help severe allergic asthma?
Managing severe asthma triggers and symptoms can feel like a constant battle. Allergens such as pollen, dust mites, pet dander, or mold can trigger asthma attacks, even with medications. One treatment that can desensitize you to these allergens is allergen immunotherapy.It’s more commonly known as allergy shots or sublingual tablets.
Allergen immunotherapy gradually reduces your body’s sensitivity to specific allergens. It involves giving small, controlled doses of the allergen over time. It is given through either injections or tablets that dissolve under the tongue. The idea is to teach the immune system to tolerate these allergens instead of overreacting. Treatment lasts 3-5 years.
Over time, allergen immunotherapy can reduce sensitivity to asthma triggers. It can also reduce asthma symptoms and improve quality of life.
Allergen immunotherapy is not recommended for everyone. It may not be suitable for people with severe asthma that isn’t well-controlled. There is a risk of a severe reaction that can worsen asthma symptoms. Consult a board-certified allergist to assess whether immunotherapy can help your severe asthma.
What Tools Can Doctors Use for Asthma Patient Visits
A checklist helps move the office visit along with patients with uncontrolled asthma
What are the long-term effects of poor asthma control?
Poorly controlled asthma with chronic inflammation can lead to serious long-term effects. These can affect your overall health and quality of life.
Airway remodeling
When there’s chronic inflammation, your body will work to correct the damage. In severe cases, this can result in airway remodeling. Airway remodeling involves thickening of airways walls and scarring. It can result in permanent changes to lung structure and loss of lung function, making it harder to breathe.
Frequent asthma attacks
Poorly controlled asthma increases the risk of life-threatening asthma attacks that require emergency medical care. Repeated attacks can weaken the lungs over time.
Increased risk of other health issues
Poor asthma control is linked to a higher likelihood of developing chronic obstructive pulmonary disease (COPD) in later life. Chronic inflammation may also increase the risk of cardiovascular issues like high blood pressure and heart disease.
Dependence on high-dose medications
Unmanaged asthma often requires higher doses of medications like oral corticosteroids. But it is usually recommended for short-term use, or a “burst.” Overuse or prolonged use of OCS and cause severe side effects. These may include weight gain, bone loss (osteoporosis), diabetes or suppressed immune function.

How should I discuss my asthma severity with my doctor?
Discussing asthma severity with a doctor is essential for getting the right care. Before an appointment, keep track of your asthma symptoms, their frequency, and your triggers. Record what happens when you take medications. Each of these can help your doctor decide the best treatment options.
Make a list of questions or concerns you want addressed. Here are some tips to make the most out of your doctor appointments:
Be honest about symptoms
Share how often you have symptoms of asthma. Discuss when symptoms are worse (during exercise, at night, or in certain environments). Be honest about your compliance with medications. Talk about how your asthma affects your daily life, like if you miss school, work, or activities.
Talk about medication use
Explain how often you use your quick-relief inhaler. Mention if you’ve noticed changes, like needing your inhaler more often or having more frequent symptoms. Using it more than twice a week may mean your asthma is not well controlled. Tell the doctor if you have missed any doses of your daily controller medication.
Share past asthma attacks
Describe any severe asthma attacks you have had in recent months. Share if they required emergency treatment, hospitalization, or oral corticosteroids. Let the doctor know if you feel scared or worried about having another attack.
Describe your triggers
Let the doctor know about anything that seems to make your asthma worse, like allergens (pets, dust, pollen), weather changes, smoke, or exercise. Mention if you’ve noticed triggers that are hard to avoid.
Discuss quality of life
Talk about how asthma affects your sleep, energy level, ability to exercise, or social life. Let your doctor know if your symptoms are stopping you from doing things you enjoy.
Ask questions
Make a list of questions you want to ask. Discuss if your current medications are the best ones for you. If your asthma is severe, ask about other treatments like biologics or specialized care.
There are many different terms your doctor may use to describe your asthma. Ask for an explanation if you don’t understand the terms your doctor uses for your condition.
Questions & Answers (Q&As) on severe asthma
Severe asthma can be challenging to manage and understand. Learning more about it can help you take control of your condition. Here are some common questions about severe asthma. Please email our editor if you would like to see a specific question addressed here.
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.
Reviewed by:
William E. Berger, MD, FACAAI, is a board-certified allergist and immunologist who serves as a media spokesperson and Chair of the Medical Advisory Council for Allergy & Asthma Network. He is a Distinguished Fellow and Past President (2002-03) of the American College of Allergy, Asthma & Immunology (ACAAI).