What is asthma?

Asthma is a long-term lung disorder that interferes with breathing. It can cause serious, recurring episodes of coughing, wheezing and breathlessness, known as asthma attacks. The trouble stems from chronic inflammation in the tubes that carry air to the lungs. While there is no cure, there are highly effective strategies for keeping asthma symptoms at bay.

Symptoms of an asthma attack

Symptoms of an asthma attack include:

• Wheezing
• Coughing, especially at night
• Shortness of breath
• Chest tightness, pain or pressure

In severe cases, an untreated asthma attack can be life-threatening.

When to seek emergency care

Some asthma attacks require emergency treatment. Call 999 if:

• You are too breathless to walk or talk or sleep
• Your lips or fingernails look blue
• Your reliever inhaler wears off quickly or doesn’t help
• Your symptoms are getting worse

These are signs that your body is not getting enough oxygen. Emergency treatment can help open the airways and restore oxygen levels.

Asthma early warning signs

Sometimes asthma causes more subtle symptoms that don’t interrupt your daily activities. However, these can be warning signs that a full-blown asthma attack is imminent. Symptoms to watch for include using you inhaler more often, changes in your peak flow meter readings, frequent coughing (especially at night), difficulty sleeping, unexplained fatigue and feeling out of breath.

What causes an asthma attack?

In people with asthma, the airways are chronically inflamed. Certain triggers can make the inflammation worse and cause a narrowing of the airways. At the same time, the body may produce extra mucous that clogs the airways. These changes work together to restrict the flow of air to the lungs. As too little air gets through, wheezing and breathlessness occur.

Asthma triggers: Allergies

Allergens that can trigger an asthma attack include:

• Mould
• Dust mites
• Cigarettes smoke
• Pollen from trees or flowers
• Foods such as peanuts, eggs or fish

If pollen is a trigger, asthma symptoms will probably be worse at certain times of year.

Asthma triggers: Pets

Pet allergies from feathered or furry friends are another common asthma trigger. The trigger can be proteins in their saliva or urine, or on fur or dander, that collect on clothing, furniture and walls. To reduce pet allergen exposure, keep pets out of bedrooms and the living room if possible. Washing or grooming pets once or twice a week may also help.

Asthma triggers: Air pollution

Outdoor and indoor air pollution can make asthma symptoms worse. Irritants include smog from traffic, cigarette smoke, household cleaners, paint fumes and even strong perfumes and scents.

Asthma triggers: Exercise

Regular exercise is good for most people, but it can also trigger asthma symptoms in some people. Having exercise-induced asthma doesn't mean you have to give up exercise. One in four of the Team GB Olympic athletics squad had asthma, including cycling gold medallist and Tour de France winner Bradley Wiggins. "It's only a hindrance if you make it one," he told Asthma UK. There are ways to control asthma so it won’t interfere with the activities you enjoy. Make sure the people you are working out with know about your asthma.

Asthma triggers: Weather

People with asthma may notice that symptoms get worse during certain types of weather. Temperature changes, wind, heat, cold, humidity, dry air and poor air quality may increase the chances of having an asthma attack. According to Asthma UK, three quarters of people say cold air triggers their symptoms. Thunderstorms can also result in more pollen in the air.

Who gets asthma?

Asthma can appear at any age, but it often develops during childhood. Those most at risk include people with allergies or a family history of asthma or other allergy conditions, such as eczema, food allergy or hayfever. Having one parent with asthma double's a child's chance of developing asthma. Being exposed to cigarette smoke in childhood and children born prematurely or with a low birth weight also have a greater chance of developing asthma.

Occupational asthma

Work-related asthma is caused or worsened by exposure to a specific substance. This can trigger asthma in three ways:

1. an allergic reaction, such as health care workers who develop an allergy to latex gloves.
2. an irritant reaction when a worker may react to dust or cigarette smoke
3. a natural reaction to a build up of chemicals in the lung after exposure to adhesives, plastics, lacquers, dyes or enzymes.

Asthma and smoking

Smoking is bad for everyone, but it’s an extra concern for people with asthma. Cigarette smoke can irritate the lungs and trigger asthma symptoms. The NHS says asthma sufferers should quit smoking and adds that smoking can also reduce the effectiveness of asthma medicines. Meanwhile, several studies suggest that adults and teenagers who smoke are more likely to develop asthma. 

Asthma and obesity

Asthma is also more common in people who are overweight or obese. Asthma UK says research shows people who eat the most fruit and vegetables have the healthiest lung function. Also, one US study showed teens with poor diets were more likely to have asthma symptoms. Symptoms of asthma may also get better if an obese person loses weight.

Asthma rates

5.4 million people in the UK now receive treatment for their asthma. Modern lifestyles may be partly blame, such as changes to housing, the food we eat and a more hygienic environment.

Diagnosing asthma

If you have symptoms of asthma, your doctor will want to check how well your lungs are working. A lung function test or spirometry measures how much air you can breathe in and out. A peak flow meter or PEFR is used to measure how fast air can be blown out of the lungs in one breath. Other airway testing may be used as well as allergy testing to help pinpoint asthma triggers.

Managing asthma: Avoiding triggers

The first step in controlling asthma is to identify triggers and then trying to avoid them. This may mean staying indoors when air quality is poor or trying mattress covers to help combat dust mites. The most effective way to fight allergens in the home is to remove or manage the source, such as pets, carpets and some types of furniture. Damp dusting and using a vacuum cleaner with a HEPA filter may also help.

Managing asthma: Hyposensitisation or immunotherapy

If you can't avoid some of the allergens that cause your asthma attacks, your doctor may recommend hyposensitisation or immunotherapy, sometimes known as allergy jabs. They may help desensitise a person to particular triggers and reduce asthma symptoms. 

Managing asthma: Long-term medication

It is virtually impossible for people with asthma to avoid all their triggers all the time. For this reason, many people take daily medication to prevent asthma attacks. Preventer inhalers contain low-dose steroids called corticosteroids and work by reducing inflammation in the airways, making them less sensitive to irritants in the air. These are often brown, orange or red.

Quick relief for asthma attacks

Even with the use of long-term medication, asthma symptoms sometimes flare up. When this happens, reliever inhalers provide quick relief. These usually contain short-acting beta-2-agonists to relax muscles around the airways, making it easier to breath again. Everyone with asthma should be given a reliever inhaler, which are often blue.

Using a peak flow meter

To determine whether your asthma is under control, your doctor will probably recommend using a peak flow meter to measure your PEFR (peak expiratory flow rate) or ’peak flow’. You blow into the device, and it measures how well air is moving out of your lungs. Keeping track of the peak flow and symptoms is important to help manage symptoms and warn of a possible asthma attack.

Asthma action plan

Most people with asthma are able to keep the condition under control. The key is to play an active role in developing a treatment plan.  Sit down with your doctor, practice nurse or asthma nurse to develop an asthma action plan. This will identify triggers, list medications and doses, and outline what to do during an attack.

Related reading

• Asthma FAQs
• Slideshow: 10 common allergy triggers
• Slideshow: Surprising sources of indoor air pollution
• Asthma and the peak flow meter
• Smoking and asthma
• Slideshow: A visual guide to understanding bronchitis