Asthma causes the airways to become inflamed and swollen, reducing the amount of air that can pass in and out of the lungs. However, there are several different types of asthma, and each has its own set of triggers.
Asthma affects around 9.4% of children and 7.7% of adults in the United States.
In many cases, asthma is a lifelong condition that a person can control using medication and by avoiding triggers that cause asthma attacks.
Although childhood asthma and adult-onset asthma have similarities, symptoms can differ in severity. Learn more about the differences between adult-onset and childhood asthma here.
Certain triggers in the environment can also worsen the symptoms of asthma and cause asthma attacks.
Keep reading to learn more about the different types of asthma, including symptoms and treatment options.
Allergic asthma is the most common type, affecting around 60% of people with asthma in the U.S.
Around 8 in 10 people with allergic asthma will also have another allergic condition, such as eczema, allergic rhinitis, or a food allergy.
Certain allergens in the environment can trigger allergic asthma. Some common allergens include:
- pet dander
- mold spores
- foods such as milk, eggs, and certain nuts
- dust mites, cockroaches, and cockroach feces
- irritants in the air, such as tobacco smoke and automobile and chemical fumes
- heavily fragranced products, such as perfumes
It is important for people with allergic asthma to seek treatment from a specialist, as this can help them manage their condition. They should also take any prescribed medication as a specialist directs.
The following tips may also help people with allergic asthma avoid common allergens:
- Vacuum and dust regularly in order to remove pet dander, dust mites, and cockroach allergens.
- Keep pets out of bedrooms.
- Avoid outside activities when pollen or air pollution levels are high.
- Avoid foods that trigger allergic reactions, such as milk, eggs, shellfish, peanuts, and tree nuts, including hazelnuts, walnuts, and almonds.
- Reduce the use of harsh chemicals or heavily fragranced products at home.
Nonallergic, or intrinsic, asthma does not require an allergen to trigger an attack.
It is less common than allergic asthma, accounting for around 10–33% of all asthma cases. It is more likely to appear in adulthood and affects more females than males.
Experts believe that nonallergic asthma develops due to genetic and environmental factors.
For example, symptoms may occur when a person has exposure to:
- irritants in the air, such as smoke
- respiratory infections, such as a cold, flu, or sinus infection
People with symptoms such as shortness of breath, wheezing, or coughing should seek help from an asthma specialist. This will help them determine what is triggering their symptoms. However, it may take longer to work out what is causing nonallergic asthma.
To manage their symptoms, they should also take any prescribed medication as a specialist directs.
In seasonal asthma, symptoms flare up in certain conditions or at particular times of the year.
For example, a person with seasonal asthma may notice that symptoms are worse, or only present, during:
- hay fever season, when pollen levels are at their highest
- cold or hot weather, thunderstorms, and sudden changes in temperature
- days when air pollution is worse, such as still, cold days
- winter months, when there are more cold and flu viruses around
In many ways, seasonal asthma is similar to allergic asthma. In fact, people may use both terms to describe asthma attacks that occur during the pollen season.
People with seasonal asthma should seek medical treatment. This will help them manage their condition during periods when symptoms are likely to get worse.
They should also take any prescribed medication as a doctor or healthcare provider directs.
The following tips may also help reduce symptoms of seasonal asthma:
- Pay attention to local weather reports on air quality and pollen levels, and only plan outside activities for when conditions are less likely to trigger an asthma attack.
- Keep windows and doors closed, both at home and when traveling by car.
- Wear a scarf over the mouth and nose in cold weather, to warm up air as it passes into the lungs.
- Keep medication on hand for quick relief from symptoms.
- Keep a diary to note which weather conditions seem to bring on symptoms.
People with occupational asthma may find that their symptoms are worse while working, or that they improve with time off work.
In fact, up to 15% of asthma cases in the U.S. may be due to job-related exposure to paint chemicals, aerosols, insecticides, or other harmful substances.
How long the symptoms take to occur may depend on the level of exposure to these and other substances. Some people may have an asthma attack within 24 hours of exposure. In others, it may take months, or even years, for any symptoms to develop.
People with occupational asthma should seek treatment from a doctor or healthcare provider. This will help them identify what is causing their symptoms, avoid further exposure, and ease their symptoms.
They should also take any prescribed medication as a doctor or specialist directs.
Exercise-induced asthma occurs when symptoms flare up during or immediately after exercise or another form of strenuous activity. This may happen around 5–20 minutes after the exercise.
Although it is common to experience shortness of breath after exercise, exercise-induced asthma may also cause coughing, wheezing, and chest pain, ranging from mild to severe.
Around 90% of people with asthma also experience exercise-induced asthma, with the majority of cases having a mild form that responds well to treatment.
The following factors may also worsen symptoms of exercise-induced asthma:
- chlorinated pools
- exposure to polluted air while running or cycling outside
- cold, dry air while ice skating or playing hockey
- warm, humid air while doing hot yoga
Asthma medications can often treat the symptoms effectively. However, it is important for people to see a doctor if their symptoms are not responding to regular medication.
The following tips may also help reduce the risk of an asthma attack during or after exercise:
- Use an inhaler before exercise and keep it close to hand when exercising.
- Avoid exercising with a viral infection.
- Warm up before exercise, to help loosen the airways.
- Cool down after exercise, to help breathing slow gradually.
- Wear a scarf over the nose and mouth when exercising outdoors.
- Avoid exercises that result in labored or heavy breathing.
Although difficult-to-control asthma is not an accepted subtype or diagnosis, some people do find their symptoms much harder to manage.
Such symptoms may happen frequently, or the person may be having life threatening asthma attacks.
There are a range of reasons that asthma can be difficult to control, including:
- having another underlying health condition, such as heart disease or diabetes
- smoking or frequently being in smoky environments
- not taking medication correctly, at the right times, or at the correct dosage
It is important for people with difficult-to-control asthma to speak to an asthma specialist about their medication and any underlying health conditions or environmental factors they think may be involved.
A specialist can help the person take their medication in the right way and at the right time. A 2017 study suggests that this can be an effective way to get asthma under control.
To discover more evidence-based information and resources for asthma & allergies, visit our dedicated hub.
Severe asthma, or brittle asthma, affects around 4% of all adults with asthma.
Experts consider asthma to be severe when symptoms do not improve with standard medications. People with severe asthma are likely to:
- have more asthma attacks than people with mild-to-moderate asthma
- spend more time in the hospital as a result of their asthma
- take steroid tablets long-term
The symptoms of severe asthma are the same as those of mild-to-moderate asthma, but they may be much more intense. They can also sometimes be life threatening.
Treatment options for severe asthma can vary depending on the symptoms and how a person responds to certain medications.
It is important to seek the advice of a specialist, who can help determine which specific treatments are best for each person.
In recent years, treatment has advanced for people with severe asthma.
Doctors are now using monoclonal antibodies to improve the symptoms associated with severe asthma. This type of treatment can also reduce the dosage of steroids that people need to take, potentially leading to a better quality of life.
Asthma refers to chronic inflammation of the airways in the lungs. It can develop or flare at any age, and the symptoms can range from mild to severe.
There are several types of asthma, which experts usually classify by their triggers. Triggers include allergens and exercise.
Regardless of its type, people can usually control asthma effectively with the right treatments.
Talking to an asthma specialist and taking medication correctly can help a person live a full and active life.
Treatment for severe asthma continues to develop.