Asthma is when your airways are hypersensitive and easily become inflamed (swollen) and narrowed, making it sometimes difficult to breathe.

By Wallace Health I Medically reviewed by Adrian Roberts.
Page last reviewed: October 2018 I Next review due: October 2023

What is asthma?

Asthma is a chronic (long-term) condition for many people, particularly if it starts when you’re an adult. Children with asthma may see symptoms improve or go away during their teenage years but asthma may come back in adulthood. 

Asthma causes your airways to become hypersensitive to certain things, which trigger an inflammatory reaction. The airway lining becomes irritated, inflamed and narrowed, and may produce extra mucus. This restricts the flow of air in and out of your lungs.

Asthma is common and affects over five million people in the UK. It often starts in childhood but adults can get it too.

You’re more likely to get asthma if you or someone in your family has another allergic (atopic) condition, such as hay fever or eczema.

Asthma symptoms range from mild, where you may not be too bothered by them, to severe, which can even be life-threatening.

Most people can manage their condition with asthma inhalers.

How to tell if you have asthma

Asthma symptoms vary from person to person. You may have:

You may notice that symptoms get worse:

  • At night
  • If you breathe in smoke or fumes
  • When you have a cold
  • With exercise

Breathing in cold, damp air can also trigger asthma symptoms.

Other conditions can cause symptoms similar to asthma. However, your symptoms are more likely to be caused by asthma if they:

  • Are worse at night and early in the morning
  • Happen in response to a known trigger for asthma, such as an allergen (eg animal fur, pollen) or exercise
  • Happen often and keep recurring

If you’re having extreme difficulty in breathing or your symptoms are suddenly worse, you may be having an asthma attack and should seek immediate medical help.

Talk to your doctor if you’re concerned about symptoms

You can book an appointment with a Spire private GP today.

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Asthma attacks

Asthma attacks can occur suddenly or gradually over a few days. Symptoms of a severe asthma attack include: 

  • A fast heartbeat
  • Being too breathless to eat, speak or sleep
  • Blue lips or fingers
  • Breathing quicker
  • Confusion, dizziness, drowsiness or exhaustion
  • Severe and constant chest tightness, coughing and/or wheezing 

You may also faint from a severe asthma attack.

Diagnosis and tests for asthma

It is important to track your symptoms and keep your doctor informed as asthma often changes over time. Your treatment may therefore need adjusting. 

Your doctor will ask you about:

  • Any medicines you’re taking — some anti-inflammatory painkillers can make asthma symptoms worse
  • Any family history of asthma or related conditions such as hay fever or eczema
  • When you get symptoms and if anything makes them worse
  • Your work, specifically if it involves breathing in dust, fumes or smoke

They will also check if you have an airway infection, which could be causing your symptoms.

They may perform tests to check your breathing and lung function. These include:

  • FeNO test — you will breathe into a machine that measures nitric oxide levels in your breath; high levels are a sign of lung inflammation
  • Peak expiratory flow meter — you will blow into a handheld device that measures how fast you can breathe out; you may need to do this several times over a few weeks to check if your measurements change over time
  • Spirometry — you will blow into a machine that measures how fast you can breathe out and how much air you can hold in your lungs

You may also need an X-ray to check your lungs.

Causes of asthma

The exact cause of asthma is not known, although genetics, pollution and modern hygiene levels have been suggested as causes — there is currently not enough evidence to support these suggestions. 

The airways of people with asthma are hypersensitive, which makes them prone to inflammation. Inflammation causes the airways to temporarily narrow, which makes breathing in and out difficult. This can happen randomly or can be triggered by:

  • Allergies to pollen or animal fur
  • Certain medications, particularly anti-inflammatory painkillers eg aspirin and ibuprofen
  • Infections such as a cold or the flu
  • Mould or cold, damp air
  • Smoke or air pollution
  • Weather — this includes: 
    • Hot and humid conditions
    • Sudden changes in temperature
    • Thunderstorms
    • Windy conditions

Asthma can also be brought on by exercise, stress or strong emotions.

Your risk of developing asthma is also higher if you: 

  • Have a family history of asthma or atopic conditions
  • Have a job that involves breathing in dust, fumes or smoke
  • Have an allergic (atopic) condition, such as a food allergy, eczema or hay fever
  • Have had bronchiolitis — this is a common childhood lung infection
  • Were born prematurely (before 37 weeks) or with a low birth weight
  • Were exposed to tobacco smoke as a child

Your risk is also higher if your mother smoked while pregnant with you.

Work-related asthma

You may develop asthma after being exposed to certain substances as part of your work. This is called occupational asthma. Common causes of occupational asthma include exposure to:

  • Animals
  • Colophony — this is often found in solder fumes
  • Flour and grain dust
  • Isocyanates — these chemicals are often found in spray paint
  • Latex
  • Wood dust

Certain jobs put you at greater risk of being exposed to these substances, including being an: 

  • Animal handler
  • Baker or pastry maker
  • Chemical worker
  • Food processing worker
  • Nurse
  • Paint sprayer, timber worker or welder

Common treatments for asthma

Currently, there is no cure for asthma. However, there are effective treatments to control your symptoms so they don’t have a big impact on your life. 

You’ll usually be prescribed asthma inhalers. There are two types:

  • Reliever inhalers for use only when you need to calm your asthma symptoms — most people with asthma are prescribed this kind of inhaler; they contain beta-antagonists, which quickly open up your airways by relaxing the muscles that cause your airways to contract; side effects include shaking or a rapid heartbeat for a few minutes after use
  • Steroid (preventer) inhalers for regular use to reduce inflammation in your airways — if you use your reliever inhaler three or more times a week, your doctor may prescribe a preventer inhaler; side effects are not common but include: 
    • A fungal infection of the mouth or throat (oral thrush)
    • A hoarse voice
    • A sore throat

Sometimes you may be prescribed a combination inhaler. These are used daily to prevent symptoms and if symptoms occur, to provide long-lasting relief. Side effects are similar to those for preventer and reliever inhalers. 

If using an inhaler alone is not controlling your symptoms, your doctor may prescribe tablets as well. 

If your symptoms don’t improve, you’ll be referred to a respiratory consultant. They can provide other treatments, such as:

  • Injections — these are given every few weeks
  • Surgery called bronchial thermoplasty — this is performed under general anaesthetic

You’ll need a follow-up appointment with your doctor once a year to check your asthma is under control and make changes to your medication if needed.

You can also reduce the chances of an asthma attack by:

  • Avoiding triggers
  • Having an annual flu jab
  • Maintaining a healthy weight
  • Stopping smoking
  • Using inhalers before you exercise

Coronavirus and asthma

There is no evidence that having asthma increases your risk of catching coronavirus. 

If you do catch coronavirus and have severe asthma or asthma that is not well controlled, you may be at higher risk of more serious illness.

During the pandemic, you should continue to get your routine asthma care.

Living with asthma

Having asthma doesn't prevent you from leading a normal life. There are simple things you can do to control your symptoms, including: 

  • Carrying your reliever inhaler with you at all times — if you notice you are using it more than usual, speak to your doctor
  • Checking if medications you need to take are suitable for someone with asthma — ask a doctor, nurse or pharmacist if you aren't sure
  • Getting the one-off pneumococcal vaccination
  • Having regular check-ups to discuss your symptoms, medications and in some cases, taking breathing tests
  • Keeping warm and dry in cold weather by dressing appropriately and breathing in through your nose to warm the air before it enters your lungs 

If you are pregnant and your asthma is getting worse, speak to your doctor. In most cases, treatment will remain the same and your symptoms will improve. However, poorly controlled asthma during pregnancy increases the risk of complications, such as pre-eclampsia and premature birth. You may therefore need to take extra precautions during labour to avoid having an asthma attack, although asthma attacks in labour are rare.

Complications of asthma

Asthma can usually be well-controlled. However, it is a serious condition that needs monitoring. You should follow your treatment plan and let your doctor know if your symptoms are getting worse. 

Poorly controlled asthma can cause:

  • Anxiety, depression and/or stress
  • Constant tiredness
  • Delays in growth or puberty in children
  • Disruption to your schedule because of unexpected visits to the hospital or to see your GP 
  • Pneumonia
  • Underperformance at or absence from work or school

Your risk of severe asthma attacks is also higher, which can be life-threatening.