Asthma - the different types explained

Asthma is a chronic condition that affects the airways and causes breathing difficulties. Asthma can’t be cured, but symptoms can be controlled with the appropriate therapy.

Asthma typically causes wheezing, shortness of breath and coughing, but there are many different types of asthma and some appear differently to others.

Some symptoms are consistent across multiple different types of asthma, while other symptoms are more commonly associated with one particular type.

It’s common for people to have more than one type of asthma at the same time.

Knowing which type of asthma you have is important as this can help ensure you get the most appropriate treatment and potentially avoid possible triggers that set off your asthma symptoms.

Types of asthma

The different types of asthma are named based on factors such as age at onset of symptoms, the severity and type of symptoms, and triggers of asthma symptoms.

The following is a list of different types of asthma:

• Pediatric or childhood asthma
• Adult-onset asthma
• Allergic asthma
• Non-allergic asthma
• Exercise-induced bronchoconstriction
• Occupational asthma
• Cough variant asthma
• Nocturnal or nighttime asthma
• Asthma-COPD overlap syndrome
• Other asthma types

Pediatric or childhood asthma

Pediatric asthma, as the name suggests, begins during childhood and affects 1 in 12 children aged from 0-17 years in the US. It’s a leading cause of missed school days. Before puberty asthma is more common in boys than girls, but after puberty this situation reverses. Boys are also more likely than girls to have severe asthma during childhood and adolescence.

The exact cause of pediatric asthma is not clear - many factors have been suggested to play a role including a pregnant person’s diet, stress levels, and antibiotic and cigarette use during the prenatal period. Exposure to cigarette smoke, air pollution, animals, mites, mold and other allergens during childhood also play a role.

The classic symptoms of asthma in children include:

• Coughing
• Wheezing
• Shortness of breath
• A feeling of tightness in the chest

Increased wheezing and difficulty breathing are common signs of a flare-up beginning.

Asthma symptoms in children are commonly triggered by colds and other infections of the upper respiratory tract. Exercise and coming into contact with allergens, smoke and other irritants are also common triggers. Symptoms may also worsen at night.

Often a diagnosis of asthma in children occurs after the child has been diagnosed with recurrent wheezing associated respiratory infections (WARIs) or reactive airway disease (RAD). Asthma also commonly occurs alongside eczema and allergies.

To diagnose asthma your healthcare provider will take a medical history and conduct spirometry tests - which require a child to breathe into a tube connected to a machine - to see how well their lungs function. Other tests that may provoke asthma symptoms, such as allergy and exercise testing, and administering methacholine - a drug that temporarily narrows the airways - may also be required.

Adult-onset asthma

Asthma affects about 1 in 13 adults in the US and is more common in women than men. Black Americans are also more likely to have asthma than white Americans. The same is also true in children.

While many people develop asthma in childhood, in some people symptoms don’t appear until adulthood. Unlike children who tend to have intermittent symptoms triggered by allergies or a respiratory infection, adults usually have persistent symptoms.

Adult-onset asthma more often develops in women, who are more likely to develop asthma after the age of 20, and obese people.

Some cases of adult-onset asthma also occur in people who had asthma as a child. In these cases symptoms often disappeared in late childhood and reemerged during the person’s 30s or 40s.

Causes of adult-onset asthma include:

• Allergies. Allergies to cats and other allergens, cause about 30 percent of cases
• Exposure to irritants in the home or workplace, such as cigarette smoke, chemicals, mold and dust. Prolonged exposure to certain materials in the workplace is also known to be a cause
• Hormonal fluctuations in women during or after pregnancy and during menopause
• Illness, including viruses and other infections

Smoking does not cause adult-onset asthma, but it can make the symptoms worse.

Symptoms of adult-onset asthma include:

• Dry cough, particularly at night or following exposure to specific triggers
• A feeling of tightness or pressure in the chest
• Wheezing when breathing out
• Shortness of breath following exercise or physical activity
• Trouble breathing
• Colds which affect the chest and linger for 10 days or more

Adult-onset asthma is diagnosed in the same way as pediatric asthma. Your healthcare provider who will take a medical history, check your lung function with spirometry tests, and possibly run other tests such as allergy tests.

Allergic asthma

Allergic asthma is the most common type of asthma, affecting about 60 percent of people diagnosed with asthma

Symptoms of allergic asthma are caused or triggered by exposure to pollen, pets, dust mites, cockroaches and other allergens.

If you have allergic asthma your immune system sees the allergens as harmful invaders and releases a substance called immunoglobulin E (IgE), which can result in swelling and inflammation of your airways. This makes it more difficult to breathe and may possibly trigger an asthma attack.

Allergic asthma causes:

• Shortness of breath
• Wheezing
• Trouble breathing
• A feeling of tightness in the chest
• Cough

Symptoms of allergic asthma may also be accompanied by allergy symptoms, such as red eyes, sneezing, a blocked nose, itching or a rash.

Allergy testing, including blood tests and skin tests, can help confirm a diagnosis of allergic asthma.

Non-allergic asthma

Non-allergic asthma (non-atopic asthma) isn’t caused by allergens, but is instead triggered by illnesses, stress, medications or environmental factors such as temperature changes. It is less common than allergic asthma occurring in between 10 and 33 percent of asthmatics. It may develop later in life and its symptoms can be more severe.

Symptoms of non-allergic asthma may be caused or triggered by viral infections of the respiratory tract, exercise, airborne irritants, stress, weather conditions, and certain medications and food additives.

The symptoms of non-allergic asthma also include shortness of breath, wheezing, trouble breathing, a feeling of tightness in your chest and cough - particularly at night, during exercise or while laughing.

The same tests used to diagnose allergic asthma are used to help diagnose non-allergic asthma, as they help to rule out allergens as the cause of asthma symptoms.

Exercise-induced bronchoconstriction

Exercise-induced bronchoconstriction (EIB) was previously called exercise-induced asthma. In people with EIB the airways narrow in response to exercise or physical activity, which makes breathing more difficult.

Up to 90 percent of people with asthma are thought to experience EIB, but EIB can also occur in people who do not otherwise have asthma.

EIB can be triggered by physical activity itself, particularly intense physical activity. It can also be triggered by irritants you come into contact with while exercising, such as chlorine while swimming, pollution while exercising outdoors or cold, dry air from an ice rink. Cold, dry air is a more common trigger of EIB symptoms than warm, humid air.

Symptoms often appear within a few minutes of starting exercise and can continue for some time after you stop exercising.

The most common symptoms of EIB are:

• Shortness of breath
• Wheezing - can often be the first sign of asthma in children
• Reduced endurance
• A feeling of tightness in the chest
• Cough
• Upset stomach
• Sore throat

As with other types of asthma, allergy testing can be useful to help rule out allergens as a cause of your asthma symptoms. To help confirm the diagnosis your healthcare provider may also use spirometry testing conducted while you exercise on a treadmill or a recumbent exercise bike.

Occupational asthma

Occupational asthma is a type of asthma that is caused by coming into contact with allergens or irritants in the workplace. It affects about 10 to 25 percent of adults with asthma.

Asthma is generally considered to be a chronic, long-term condition, but occupational asthma may be reversible if the cause can be avoided.

Occupational asthma can be caused by a range of allergens and irritants, including:

• Flour dust
• Food additives
• Latex
• Animal dander and saliva
• Dust - especially from grains, poultry and wood
• Vapors, fumes, and mists
• Chemicals

Symptoms of occupational asthma may take time to develop. As your sensitivity to the allergen or irritant increases your symptoms become worse. Symptoms may include:

• Shortness of breath
• Wheezing
• A feeling of tightness in the chest
• Red, itchy, inflamed eyes (conjunctivitis)
• Blocked, runny or itchy nose (rhinitis)

If you suspect you have occupational asthma then visit your healthcare provider. Your healthcare provider will likely run the same tests as used to diagnose other types of asthma, and if a particular allergen or irritant is suspected they may also conduct a challenge test to see how you respond.

Cough variant asthma

Cough variant asthma (CVA), is a type of asthma that causes a dry, nonproductive cough as the only symptom. It is a common cause of chronic cough and may result in the development of other asthma symptoms if left untreated. CVA can develop at any age, but it typically develops in young children.

Often people with CVA have seasonal variation in their symptoms, indicating that allergens play a role in triggering CVA symptoms in many cases. Other causes of CVS, such as strong fragrances or cold air, can also trigger symptoms.

CVA can be difficult to diagnose because lung function tests, such as spirometry tests, may produce normal results. Methacholine challenge testing is sometimes used, but another option that your healthcare provider may use to confirm a diagnosis of CVA is to prescribe you a bronchodilator - a medication that opens up your airways and is used to treat asthma. If this medication improves your cough then it indicates that you may have CVA.

Nocturnal or nighttime asthma

As many as three quarters of the people who have asthma report having symptoms at night.

The symptoms of nocturnal or nighttime asthma can occur just before bedtime or develop at any point during the night.

Symptoms of nocturnal asthma include the usual asthma symptoms of a cough, a feeling of tightness in the chest, wheezing and shortness of breath. Nocturnal asthma can also disrupt your sleep, leaving you feeling tired during the day and making it more difficult to concentrate. It may also make it more difficult to control your asthma symptoms during the day.

Symptoms of nocturnal asthma may be triggered by lying on your back while you sleep. Lying on your back can make it harder to breathe and also allow mucus from your nose to drip down the back of your throat, which can make you cough. If you get acid reflux from lying down then this might also irritate your airways.

Exposure to dust mites, pet dander, mold and other allergens in the bedroom or during the evening can also make asthma symptoms worse at night, as can exposure to cooler night air. Changes in hormone levels during sleep may also contribute to the development of asthma symptoms at night.

Talk to your healthcare provider if you think you have nocturnal asthma. They may recommend you use a peak flow meter at home, which is a small plastic device you blow into. A peak flow meter measures how quickly you can blow air out of your lungs and tells you how open your airways are. Taking measurements during the day and night to check your lung function can help to confirm whether you have nocturnal asthma.

Asthma-COPD overlap syndrome

Asthma and chronic obstructive pulmonary disease (COPD) are conditions that can make breathing more difficult and share many of the same symptoms. Some people with asthma can also develop COPD and this is known as asthma-COPD overlap syndrome (ACOS).

People with ACOS typically have reduced lung function and more frequent and severe symptoms including:

• Shortness of breath
• Wheezing
• Cough
• Trouble breathing
• Feeling tired
• Excess mucus production

It’s important to find out if you have ACOS because it can be more serious than asthma on its own. Your healthcare provider will take a medical history and perform a physical exam. As well as conducting other tests for asthma they may recommend a chest x-ray or CT scan.

Other types of asthma

In addition to the types of asthma listed above, the following terms are also used to help describe the different types of asthma.

• Seasonal asthma. Seasonal asthma is a term used to describe a type of asthma that only flares up at certain times of the year. Seasonal asthma may be triggered by allergies or cold weather for example.
• Difficult asthma. Difficult to control asthma is thought to affect about 17 percent of people with asthma. People with difficult to control asthma have breathing difficulties most of the time and are prone to life-threatening asthma attacks. Having other health conditions, smoking, irregular medication use and poor inhaler technique can contribute to the symptoms of difficult asthma.
• Severe asthma. Severe asthma, which was also known as brittle asthma, is a rare form of asthma affecting about 4 percent of people with asthma. People with this type of asthma have uncontrolled symptoms despite being highly medicated and following their treatment plan. There are two main types of severe asthma including:
  • Type-2 inflammation - includes allergic asthma and eosinophilic asthma (e-asthma). Eosinophils are a type of white blood cell that help fight disease and infection.
  • Non-type-2 inflammation - includes non-eosinophilic asthma. In people with this type of asthma the airways are inflamed despite there being few to no eosinophils. Non-eosinophilic asthma does not respond well to the inhaled corticosteroids typically used to treat asthma.
• Intermittent asthma. Intermittent asthma is the mildest form of asthma. Without medication people with this type of asthma experience asthma symptoms on fewer than 2 days per week and have nighttime symptoms on fewer than 2 nights per month. Symptoms do not interfere with normal activities and lung function tests are normal between asthma attacks.
• Persistent asthma. Persistent asthma can result in mild, moderate or severe asthma symptoms.
  • Mild persistent asthma. Without treatment people with mild persistent asthma may have symptoms more than 2 days per week, but not every day. They may have nighttime symptoms 3 to 4 nights a month. Asthma attacks may also interrupt daily life. Lung function tests are normal between attacks. The results of lung function tests may vary a little between morning and afternoon, but test results fall within 80 percent or more of the expected range.
  • Moderate persistent asthma. Without treatment people with moderate persistent asthma may have symptoms every day and nighttime symptoms more than once a week, but not every night. Lung function test results fall between 60-80 percent of the expected range. Test results will also vary more than 30 percent between morning and afternoon.
  • Severe persistent asthma. Without treatment people with severe persistent asthma experience symptoms throughout the day. Symptoms also severely limit their physical activity on a daily basis. Lung function test results will be 60 percent or less of the expected value. Test results also vary more than 30 percent between morning and afternoon.
• Thunderstorm asthma. Thunderstorm asthma is a type of asthma that is caused by grass pollens spread by thunderstorm conditions. Pollen grains are drawn up into the storm clouds as they form. The grains absorb water, swell and burst open, which releases pollen-containing particles that are small enough to be breathed in during a thunderstorm.

Bottom line

If you’re diagnosed with asthma, talk to your healthcare provider to find out what type of asthma you have. Work with them to develop a treatment plan and remember to take your asthma medications regularly as prescribed. Many people find that with good management they are able to keep their asthma symptoms under control.