In the UK, 5.4million people have asthma and, for many, allergies could trigger a life-threatening asthma attack. But the link between asthma and allergies is widely misunderstood.

Dr Andy Whittamore is Clinical Lead at Asthma UK, the only UK asthma charity, which funds research into a cure for asthma and provides asthma health advice. Here, he reveals the truth about asthma and allergies.

1. Allergies and asthma are not the same thing

“Many people confuse asthma and allergies, but they are separate conditions,” says Dr Andy Whittamore.

“They are linked though and for some people with asthma, an allergy could trigger a potentially life-threatening asthma attack.”

When someone is having an allergic reaction, the immune system overreacts and releases a chemical called histamine. This chemical causes the nose, eyes, throat and sinuses to become swollen, irritated and inflamed.

For many people with asthma, this release of histamine can make asthma symptoms worse because it means their airways get narrower. This makes it more difficult to breathe and causes symptoms like wheezing, coughing and breathlessness. These can lead to a life-threatening asthma attack.

“Some allergens, such as dust mites, are impossible to avoid so the best way to reduce asthma symptoms is to look after your asthma and make sure it’s well managed,” says Dr Whittamore.

“At Asthma UK, we’d advise people with asthma who have allergies to take their preventer inhaler, which is usually brown, every day, as prescribed.

“It helps to control inflammation in your lungs, meaning you’re less likely to have an asthma attack even if you do come into contact with a trigger. If you have asthma symptoms you should use your reliever inhaler, which is usually blue.”

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2. You can have asthma even if you have no allergies

It is possible to have non-allergic asthma, where your symptoms are caused by other factors, such an irritant you breathe in, rather than an allergic reaction. Common irritants include cigarette smoke and car exhaust fumes. Common factors that can trigger asthma symptoms include exercise, cold weather, and colds and flu.

It is also possible that your asthma can be triggered by both an allergic reaction and irritants like cold weather. On average, each person with asthma has around six triggers.

“Asthma is serious and every day in the UK, three people die from an asthma attack, so it’s vital you stay well with your asthma,” says Dr Whittamore.

“People are less likely to have an asthma attack if they get into a good routine of taking their asthma medicine so we’d advise they take their brown preventer inhaler as this builds up protection in their airways over time and means they are less likely to have an asthma attack. It also reduces inflammation so the airways are less irritable and sensitive so less likely to react to a trigger.”

Dr Whittamore adds: “People with asthma should also follow their written asthma action plan as it explains what they need to do to control their asthma and when they should seek medical advice.

“If your reliever inhaler is not lasting four hours, this is an emergency and you need to discuss your case immediately with a GP or nurse.”

3. Hayfever is one of the main asthma triggers

“You are more likely to suffer from asthma if you have an allergy like hay fever,” explains Dr Whittamore. “Studies show that when there is a higher concentration of grass pollen in the air, more adults are admitted to hospital because of their asthma.”

“People with asthma can also be sensitive to tree and weed pollens. Asthma UK recommends keeping a diary to help you notice if pollen is a trigger, and to keep an eye on the pollen count.

“Different types of pollen are released at different times of the year. In the UK, tree pollens tend to affect people from March to May each year, but can cause symptoms from as early as January.

“You can speak to your GP, nurse or pharmacist about hay fever medicines that can help your symptoms and reduce your chance of an asthma attack. If you’re out on a day when the pollen count is high, we’d advise people to make sure they take their blue reliever inhaler with them – this could be a lifesaver.”

4. Allergies to pets are not a main cause of asthma

“Many people think that pets are the main cause of asthma. It is true that all animals, including dogs and cats, produce dander, urine and saliva that can trigger asthma but animals are not the only asthma trigger, says Dr Whittamore.

“New research by Asthma UK shows that the most common asthma triggers are cold air, and colds and flu, followed by dust, air pollution, cigarette smoke and perfume.

“We’d advise people whose asthma is triggered by pet hair to take an antihistamine or nasal spray before coming into contact with an animal.

“If people cannot avoid regularly coming into contact with animals it is important that they take their preventer inhaler every day as prescribed. We advise they talk to their GP or asthma nurse about using a regular nasal spray to help control allergic nose symptoms.

“And for those who decide to carry on living with pets when they have allergic asthma, they can cut their risk of symptoms by keeping their pets out of their bedroom and living area, regularly grooming and bathing cats and dogs, or using air filters and an efficient vacuum cleaner.”

5. Food allergies are linked to asthma - but it's rare

“There is some evidence that if you have both asthma and a food allergy, you may be at greater risk of having an asthma attack that’s life-threatening, so it’s important to strictly avoid the food you are allergic to,” says Dr Whittamore.

“People with food related allergy triggers should have been told by their GP, what they need to do if they have an allergic reaction; have access to emergency medication (an adrenalin injection) and call an ambulance.”

The good news is that only a small number of people with asthma also have a food allergy. If you’re concerned you may have an allergy but haven’t been diagnosed, speak to your GP or asthma nurse or contact Asthma UK.

6. You can be allergic to mould

“Many people don’t realise that you can have an allergic reaction to mould and damp,” says Dr Whittamore, “Or, more specifically, to the ‘seeds’ called spores that moulds and other fungi release into the air.”

Moulds and fungi are common, and research shows they can have a big impact on your asthma symptoms. In fact, 42% of people with asthma say mould or fungi can trigger their asthma.

It’s hard to avoid mould entirely, so it’s important for people to to manage their asthma.

If you’ve been prescribed a preventer (usually brown) inhaler, take it every day, as prescribed. It helps to control inflammation in your lungs, meaning you’re less likely to have an asthma attack even if you do come into contact with a trigger such as mould.

And if you have mould in your home, don’t try to remove the mould by yourself. Ask a friend, family member or a professional to remove it for you instead and keep the room ventilated as the mould is being removed.

Asthma UK provides advice and guidance to people with the asthma through its website and nurse-staffed telephone helpline. It also funds research into a cure for asthma. Visit or call 0300 222 5800 (Monday-Friday, 9am-5pm).

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