There’s no cure for asthma, but it can be controlled by taking medication – including inhalers – and avoiding the triggers that bring on attacks.
People with asthma have very sensitive airways, which become inflamed, tight and sometimes clogged up with sticky mucus, when they breathe in anything that irritates the lungs. This restricts air flow in and out of the lungs, making it harder to breathe.
Common asthma triggers include allergens, including animal fur, house dust mites and pollen; irritants, such as cigarette smoke and strong fumes; infections, including colds, flu and sinus infections; weather conditions (cold weather, damp weather, sudden changes in temperature and thunderstorms) and exercise.
The exact cause of asthma is unknown, although you’re more likely to develop it if you have a family history of asthma, eczema or allergies, had bronchiolitis as a child, were born prematurely or your mother smoked during pregnancy. Menopausal women may even have a higher risk of asthma, because of falling oestrogen levels.
One explanation for asthma is the so-called ‘hygiene hypothesis’, experts argue that we've become too clean and this has resulted in many children no longer being exposed to environmental factors – such as dirt and infections – that may strengthen their immune systems.
Symptoms vary but the most common symptoms include wheezing, shortness of breath, tightness in the chest and coughing.
The body produces hormones called steroids, which help to dampen down inflammation (including in the airways). However, this process stops while you're asleep, which means asthma symptoms are typically worse at night and first thing in the morning.
When asthma symptoms get worse, this is known as an asthma attack. An attack can happen suddenly or gradually over a few days.
There isn't just one test for asthma which can give you a diagnosis. Your GP may diagnose it from your symptoms, but they may also carry out some breathing tests. One of these is a spirometry test, which measures the amount of air you can breathe in and out and its flow rate. The other is a peak flow test, which measures the rate at which you can force air out of your lungs. These tests are not suitable for children, and a GP may diagnose them by seeing if their asthma responds to other treatments.
Your GP or asthma specialist may also measure how your airways react to a trigger by using an airway responsiveness test. If your symptoms are triggered by an allergy, you may have further allergy tests to find out the cause.
Who gets asthma?
Around 5.4 million people in the UK are treated for asthma. It’s more common in women than men but affects more boys than girls.
Asthma commonly starts in childhood, but can begin at any age. One in three children with asthma will still have symptoms when they grow up. It tends to run in families, especially when there’s a history of allergies and/or smoking.
Although there’s no cure, there are effective treatments to help manage asthma. Asthma medicines are usually given by an inhaler, which is a device that delivers medicine to your airways.
The main ones are 'preventer' inhalers, which contain inhaled steroids that stop asthma attacks occurring by reducing sensitivity, swelling and inflammation in the airways. There are also 'reliever' inhalers, which contain medication called short-acting beta agonists (SABAs), also known as salbutamol (Ventolin®). They work by relaxing the muscles around the airways and are only needed when symptoms start.
Other treatments include tablets and the bronchial thermoplasty procedure, which helps to open the lungs and ease your breathing by applying heat using radio frequency to inside the airways.