What is Asthma?

Asthma is a chronic lung condition that affects your airways or bronchial tubes. It causes your airways to narrow, swell and produce extra mucus, which in turn makes it more difficult to breathe. The narrowing of the airways causes you to feel short of breath, wheezy or trigger fits of coughing.

Asthma can affect people of all ages but while it might be mild for some, for others it can be more severe. For those severely affected, it can have a major impact on normal everyday activities or cause life-threatening asthma attacks.

There is no cure for asthma. However, it can be effectively managed and the symptoms controlled. Not everyone with asthma has exactly the same symptoms or severity and it can change over time. This is one reason why it’s important to have regular checks with your doctor or asthma nurse, so they can monitor your asthma and adapt your treatment if necessary.

Read below to discover the facts about the chronic lung condition asthma, the symptoms and causes, different types and how it is diagnosed and treated.

Asthma Symptoms

Some of the common signs and symptoms include:

  • Shortness of breath
  • A feeling of pressure, tightness or pain in your chest
  • Coughing
  • A whistling or wheezing sound when you exhale (wheezing is especially common in children with asthma)
  • Attacks of coughing and wheezing that are made worse when you have a cold, flu or other respiratory illness
  • Trouble sleeping at night due to being short of breath, coughing or wheezing.

Not everyone who has asthma has exactly the same symptoms and different symptoms may occur at different times of the year and at different times during your life. Symptoms can also vary from mild to more severe.

If your asthma is changing or flaring up, then you may find symptoms become worse than usual. You may find it more difficult to breathe, experience more wheezing and need to use a quick-relief inhaler more often.

What happens during an asthma attack?

When an asthma attack occurs, the muscles around the airways will first tighten – this is called a bronchospasm. A bronchospasm makes your chest feel tight and makes it harder to catch your breath. You may make a whistling sound when you try to breathe, or start wheezing. The lining in the airways will become inflamed and swollen, more mucus will be produced, plus the mucus will be thicker than usual.

If you have mild asthma, taking your reliever inhaler should start to help the attack within minutes. But if you have more severe asthma, you may need medical attention, as it can be life-threatening.

Early warning signs of an asthma attack

Asthma is a long-term chronic condition, but when an asthma attack happens, it’s an acute occurrence. This means it’s a sudden attack that happens for someone suffering with a chronic condition.

There are some early warning signs that you can look out for that may suggest an asthma attack is likely. The symptoms are usually mild, but can be useful to recognise so that you can do your best to prevent a full-blown asthma attack.

The early warning signs and symptoms to look out for include:

  • Shortness of breath
  • Extreme tiredness when exercising
  • Wheezing and coughing after exercising
  • Having a frequent cough, especially if it’s worse at night
  • A decrease in your usual lung function (which can be measured by using a peak flow metre)
  • Allergies or a cold, including nasal congestion, sneezing, sore throat and a headache.

If you have a personal asthma action plan in place, then you could adjust your medication in line with these early warning signs. If you don’t have an action plan, or you have the symptoms of an asthma flare-up, ask your doctor for advice.

What are the causes?

The exact cause of asthma is unknown and the triggers can vary from person to person. However, it is recognised that asthma runs in families (if a parent or sibling has asthma, you’re more likely to have it too) and that environmental factors can play a part.

Asthma often occurs as the result of an immune system response to an environmental allergen, such as pollen or dust mites. Not everyone exposed to the same allergen reacts to it, or may react differently. Although the reasons why a particular allergen affects one person more than others isn’t entirely clear, it’s possible that inherited genes may be involved.

Some risk factors that can increase your chances of developing asthma include:

  • Genetics – having a family member, such as a parent or sibling, who has asthma
  • Having an allergy, such as hay fever, eczema or a food allergy (these are known as atopic conditions)
  • Being a smoker
  • Being exposed to secondhand or passive smoke, including during childhood or pregnancy
  • Having had bronchiolitis (a lower respiratory tract infection) as a child
  • Being born prematurely or with a low birthweight.


The airways to the lungs are normally open, allowing air to move freely in and out of the lungs. However, people who have asthma have sensitive airways that are irritated and inflamed. Asthma symptoms are caused when the airways tighten or constrict in response to triggers, resulting in less space in the airways to breathe through.

The symptoms can be triggered by various irritants, substances and circumstances. The known triggers include:

  • Exposure to smoke, pollution or fumes
  • Respiratory infections such as colds or flu
  • Allergic reactions, such as to dust mites, animal fur, feathers or pollen
  • Changes in weather, including cold air, thunderstorms, heat, humidity or any sudden change in temperature
  • Taking medicines, such as anti-inflammatory painkillers
  • Experiencing strong emotions such as stress
  • Being exposed to damp or mould
  • Physical activity, especially if doing so in cold and dry weather
  • Sulphites and preservatives added to some foods and beverages, including dried fruit, shrimp, processed potatoes, beer and wine
  • Gastroesophageal reflux disease (GERD), where stomach acid comes back up into your throat.

If you’re aware what your potential triggers are you should try to avoid them, where possible, to help control your asthma.

Types of asthma

Unlike some other health conditions, there’s no single form of asthma – it affects different people in different ways. As knowledge and understanding has improved over the years, medical experts have identified various types.

Knowing which type of asthma you have can help you learn how to manage it more effectively and reduce the risk of coming into contact with known triggers.

Allergic asthma

Allergic, or atopic asthma, is a type of asthma triggered by allergens, such as pollen, dust mites, pet fur or feathers. If you have allergic asthma, you’ve got a higher chance of also having other forms of allergies, such as hay fever, food allergies or eczema.

Occupational asthma

It is caused by your occupation or work. It’s often associated with allergic asthma and can be triggered by exposure to fumes, chemicals, dust or other triggers you encounter on a regular basis during the course of your work.

Seasonal asthma

It only occurs at certain times of the year. Symptoms may flare up in the summer when pollen levels are high, or in the winter when the weather is very cold.

Non-allergic asthma

Non-allergic-, or non-atopic asthma, is a form of asthma that isn’t triggered by an allergy. This type often starts later in adulthood.

Exercise-induced asthma

In some cases, it can be triggered by physical exertion and is called exercise-induced asthma. Symptoms can get worse both during and after exercising.

Childhood asthma

Childhood asthma is common and first occurs during childhood. Sometimes this type can get better or even disappear completely as you get older, although it can also return during adulthood.

Adult-onset asthma

Adult-onset asthma is so-called as it starts in adulthood, rather than childhood. It’s sometimes referred to as late-onset asthma. It can be caused by occupational and environmental factors, female hormones, smoking and stressful life events.

Difficult asthma

Difficult asthma is a type of asthma that’s difficult to manage and control. The symptoms are more likely to continue, despite treatments, and frequent attacks are common.

Severe asthma

Severe asthma affects people intensely and can have a major impact on daily life. You’re more likely to have severe asthma if your symptoms are ongoing despite being prescribed higher doses of inhaled steroids or other medications, and you may need long-term steroid tablets.


If your doctor suspects you could have asthma, they’ll ask about your symptoms and undertake tests to diagnose it. They’ll look at your nose, throat, and upper airways, listen to your breathing using a stethoscope and take a general medical history.

Lung function tests will be carried out to see how well your lungs work. Common tests used include:

  • Spirometry – where you blow into a machine that measures how fast you can breathe out and how much air you can hold in your lungs.
  • Peak flow test – where you blow into a small handheld device, and it measures how quickly you can breathe out.
  • FeNO test – where you breathe into a machine that measures the level of nitric oxide in your breath (this can highlight lung inflammation).

Sometimes, you may have a chest x-ray to rule out other causes of your symptoms.

Depending on the results of your tests, your asthma will be classified into one of four general categories:

Asthma ClassificationSigns & Symptoms
Mild intermittentMild symptoms up to two days a week and up to two nights a month
Mild persistentSymptoms more than twice a week, but no more than once in a single day
Moderate persistentSymptoms once a day and more than one night a week
Severe persistentSymptoms throughout the day on most days and frequently at night

Treatment and medicines

Asthma treatment and medicines help to control symptoms, so you can live an active and normal life. As everyone experience asthma differently, your doctor will put together an asthma treatment plan designed specifically for you.

The two types of inhalers that are used to relieve and prevent asthma are:

  • Reliever inhaler – this is used to treat your symptoms when they occur and usually works within minutes. The inhaler is normally blue.
  • Preventer inhaler – this contains steroid medicine and is used daily, as prescribed, to reduce the amount of inflammation and sensitivity in your airways. It will help stop asthma symptoms occurring and is normally brown.

Depending on your symptoms, tablets or other treatments may also be prescribed. Complementary therapies, such as special breathing exercises, may be recommended to help you learn to breathe better with asthma and increase your overall lung capacity, strength and health.