How the weather affects your asthma

Ask any one of the 5.4 million people in the UK affected by asthma and they’ll tell you that summer can be a particularly trying time.

Two thirds of those with the long-term breathing condition find air pollution triggers their symptoms, and allergies to pollen, such as grass pollen, can also cause an asthma attack. As many as 60% of people with asthma also suffer with hay fever.

"Over the summer months, people with asthma are exposed to pollen, air pollution and smoke from barbecues and cigarettes, and being around many triggers at the same time can put people at an increased risk of a life-threatening attack," says respiratory physiotherapist Sonia Munde of charity Asthma UK.

Pollen and pollution

People with asthma have airways that are more sensitive to allergens such as pollen, a top trigger for asthma attacks in summer, affecting an estimated 3.3 million people in the UK.

When someone with 'allergic asthma' breathes in something they are allergic to - such as pollen from birch, oak and pine trees, as well as grasses and weeds - their airways become narrow and inflamed, leading to asthma symptoms.

High humidity and thunderstorms in summer trap these particles in the air for longer and break them into much smaller pieces, meaning they are inhaled much more deeply into people's lungs.

'Non-allergic asthma' is triggered by an inhaled irritant such as pollution from vehicles and factories, or smoke, all of which can irritate and inflame the airways.

Why hay fever can make asthma worse

People with asthma who also have a pollen allergy not only experience classic hay fever symptoms, such as itchy eyes and a running nose, but are also at an increased risk of a life-threatening attack.

Research by Asthma UK reveals that people with asthma say hay fever can disrupt their work and has even caused teenagers to drop an exam grade.

"Both asthma and hay fever are caused by 'atopy', ie a tendency to allergies," explains GP Dr Clare Morrison. "Hay fever is when the lining of the nasal passageways is ultra-sensitive, and asthma is when the lining of the lung airways is affected.

"Those who suffer from both may get relief from taking antihistamines. It's important to keep the nose clear, as breathing through the nose, rather than the mouth, helps to filter out pollen and pollution that would otherwise get into the lungs.

"A steroid nasal spray, mentholated sweets, and steam inhalations with the addition of eucalyptus oil can help keep the nose clear. It's also important to blow the nose regularly and avoid sniffing."

Why are inhalers so important?

An asthma attack occurs when something triggers the muscles in their airways - the tubes that carry air in and out of your lungs - to tighten, causing sticky mucus to build up. This narrows the airways and makes it hard for people to breathe, leading to chest tightness, wheezing, coughing or waking at night with a cough.

Most people with asthma are prescribed two types of inhalers; a preventer inhaler (usually brown) and a reliever inhaler (usually blue). The former helps to reduce the sensitivity and inflammation in the airways, meaning sufferers are less likely to experience symptoms and have an asthma attack.

People with asthma may feel generally better during the summer months as there aren't as many cold and flu viruses going around. However, this may mean sufferers are less likely to take their preventer inhaler, which could make them more likely to react to their asthma triggers.

"Preventer inhalers are a long-term treatment and taking them regularly as prescribed - usually every day - is the most important thing people with asthma can do to manage their asthma," states Munde.

"Everyone with asthma should also make sure they carry their reliever inhaler with them at all times, as they're used to quickly treat the symptoms of asthma during an asthma attack.

"I recommend that patients ensure they have sufficient reliever inhalers (usually salbutamol), but don’t simply rely on increasing the usage of these," adds Morrison. "If symptoms start to deteriorate, it's important to step up the use of 'preventer' inhalers (steroids), to avoid problems escalating further.

"If in doubt see your GP or asthma nurse for a check-up and advice."

Practical advice for summer

A common-sense action plan can help limit asthma sufferers' exposure to triggers like pollen and pollution this summer.

Keep an eye on the weather (particularly humidity) and the pollen count. When it's high, try to stay indoors, particularly at the start and end of the day, when levels are higher, and keep windows shut.

Avoid parks and gardens, and take a shower and change your clothes when you get back indoors to wash away any pollen particles in your hair.

Dust regularly with a damp cloth to minimise pollen inside the house; use a vacuum cleaner that's efficient at blocking very fine particles; and avoid drying clothes outside on high count days as pollen particles can stick to clothes and sheets, which can make symptoms worse at night time.

If pollution triggers your asthma symptoms, Munde recommends heading out in the morning when the air quality is higher.

"It's better to go out in the morning in order to avoid higher levels of pollution," she says. "If this isn't possible, try to stick to back streets where there are fewer cars, and try to avoid exercising close to main roads."

For more information on managing your asthma triggers, visit Asthma UK.