Asthma is a common lung condition that causes occasional breathing difficulties.
It affects people of all ages and often starts in childhood, although it can also appear for the first time in adults.
There's currently no cure for asthma, but there are simple treatments that can help keep the symptoms under control so it doesn't have a significant impact on your life.
Some people, particularly children, may eventually grow out of asthma. But for others it's a lifelong condition.
This page covers:
The main symptoms of asthma are:
The severity of the symptoms varies from person to person. They usually come and go, but for some people they're more persistent.
Asthma symptoms can sometimes get temporarily worse. This is known as an asthma attack.
Read more about the symptoms of asthma.
See your GP if you think you or your child may have asthma.
Your GP will usually be able to diagnose asthma by asking about your or your child's symptoms and carrying out some simple breathing tests.
But these are often difficult to do in infants and young children, so the diagnosis may be made on the basis of symptoms and response to a trial of treatment with an inhaler.
Read more about how asthma is diagnosed.
Asthma is caused by inflammation (swelling) of the breathing tubes that carry air in and out of the lungs.
This inflammation makes the breathing tubes highly sensitive, so they temporarily become narrow. This may occur randomly, or after exposure to a trigger. The tubes may also sometimes become clogged with sticky mucus.
Common asthma triggers include:
The reason why some people develop asthma isn't fully understood, although it's known that you're more likely to develop it if you have a close relative with the condition.
Read more about the causes of asthma.
While there's currently no cure for asthma, there are a number of treatments that can help control the condition.
Most asthma treatments are taken using an inhaler, a small device that delivers a spray or powder medicine to your breathing tubes as you breathe in.
The main treatments are:
You'll usually draw up a personal action plan with your doctor or asthma nurse. This will include information about your medicines, how to monitor your condition and what to do if you have an asthma attack.
Asthma is a long-term condition for many people – particularly if it first develops in adulthood.
In children, it sometimes disappears or improves during the teenage years, although it can return later in life.
The symptoms can usually be controlled with treatment and most people will have normal and active lives, although some people with more severe asthma may have persistent problems.
Although asthma can normally be kept under control, it's still a serious condition that can cause a number of complications.
This is why it's so important to follow your treatment plan and not ignore your symptoms if they're getting worse.
Badly controlled asthma can cause issues such as:
There's also a risk of life-threatening complications, such as severe asthma attacks.