Asthma tests and inhalers: what the 2024 UK guideline changed

You get wheezy every time you catch a cold. Or a cough keeps waking you at night, weeks after the cold itself has gone. Maybe you have had a blue inhaler since school and reach for it more often than you would like.

Asthma is long-term inflammation of the airways, which makes them tighten and narrow when something irritates them. About 7.2 million people in the UK have it, around 8 in every 100. It is very treatable, and the way UK doctors diagnose and treat it changed in late 2024.

If you would rather have it checked than read about it, a private GP consultation at our Harley Street clinic is £150, seven days a week, and the doctor can run spirometry and a FeNO breath test here in the clinic.

What are the symptoms of asthma?

The four main symptoms are wheezing (a whistling sound as you breathe), breathlessness, a tight chest and coughing. They tend to be worse at night, early in the morning, during exercise, or around triggers such as cold air, pollen, dust, pets, mould or cigarette smoke.

Not everyone gets all four. For some people a persistent cough, especially at night, is the only sign. This is called cough-variant asthma, and it is often missed because people rarely link a cough with asthma.

Asthma can start at any age. Adult-onset asthma is common and can follow a chest infection, hormonal change, an allergy or something breathed in at work, such as flour dust or chemical fumes. Colds and flu, stress and some medicines, including aspirin, ibuprofen and beta-blockers, can set off symptoms too.

How is asthma diagnosed now?

NG245 asks doctors to confirm asthma with an objective test rather than on symptoms alone. For adults, the order is set out below. You only move to the next step if the one before leaves the answer open.

How asthma is confirmed in adults (NICE, BTS and SIGN, NG245, 2024)

Children aged 5 to 11 start with FeNO, and a level of 35 ppb or more confirms asthma. If it is not raised, spirometry follows, with a 12% rise in FEV1 counting as reversibility.

FeNO is a simple breath test. You breathe out slowly and steadily into a handheld device, and it measures nitric oxide, a marker of the type of airway inflammation that steroid inhalers treat. A high reading also tells the doctor that a steroid-containing inhaler is likely to help.

Spirometry measures how much air you can blow out and how fast. You blow into the machine, take a reliever inhaler, then blow again to see whether your airways open up. Both tests are done here at the clinic. The eosinophil count comes from a full blood count, which costs £63.75 plus the £50 phlebotomy fee, with results usually back in 1 day.

What changed in asthma treatment in 2024?

For years, most people were given two inhalers: a blue reliever (salbutamol) for symptoms and a steroid preventer to take every day, with a long-acting bronchodilator added if that was not enough. NG245, published in November 2024, replaced that ladder.

The one thing worth remembering is this. A blue inhaler opens the airways for a few hours but does nothing for the inflammation underneath. The newer reliever combines a low dose of inhaled steroid with formoterol, a bronchodilator that works within minutes, so every puff you take for symptoms also treats the cause. This is called anti-inflammatory reliever (AIR) therapy.

Treatment steps for people aged 12 and over (NG245)

People using MART do not normally need a separate blue inhaler. The guideline also says that anyone with confirmed asthma who uses a blue inhaler on its own should be moved onto an AIR inhaler. At the time of writing, only certain budesonide and formoterol inhalers are licensed for AIR therapy, so the doctor will choose the device with you and check your technique.

Children aged 5 to 11 usually start on a low-dose children's steroid inhaler with a blue reliever as needed, moving to children's MART if that is not enough. Children aged 3 months to 15 years are seen in our paediatric clinic on Monday and Wednesday, where the consultation is £200.

Signs your asthma needs a review

NG245 lists the patterns that put someone at higher risk of a serious attack. If any of these sound familiar, book a review:

• you get through more than 2 reliever inhalers a year;
• you have needed 2 or more courses of steroid tablets in a year;
• you have been to A&E or admitted to hospital with asthma;
• you wake at night with cough or wheeze, or use a reliever more than twice a week;
• you have never been shown how to use your inhaler, or have no written asthma action plan.

Inhaler technique matters more than most people realise. Studies consistently show that many people do not use their inhaler correctly, so much of the medicine misses the airways. Checking technique is the first thing a doctor looks at when asthma is not controlled.

Every person with asthma should have a written action plan that says what to take day to day, what to do when symptoms build, and when to get emergency help. We review asthma at least once a year, or sooner if things change.

What to do in an asthma attack

Signs of an attack include a reliever that is not helping, being too breathless to speak, eat or sleep, breathing that keeps getting worse, or lips and fingertips turning blue. Sit upright and try to stay calm, then:

• with a blue reliever: take one puff every 30 to 60 seconds, up to 10 puffs;
• with an AIR or MART inhaler: take one puff every 1 to 3 minutes, up to 6 puffs.

Call 999 if you feel worse at any point or are not better after those puffs. If the ambulance has not arrived after 15 minutes (or 10 minutes on an AIR or MART inhaler), repeat the same steps.

Asthma care at 117a Harley Street

A GP consultation (£150) covers your history, an examination, spirometry and FeNO here in the clinic, a check of your inhaler technique and a written action plan. If you are on the older two-inhaler treatment and still have symptoms, the doctor can talk you through moving to AIR or MART. Any test that costs more than the consultation is explained before it goes ahead.

When breathlessness needs a chest X-ray, we can do it on site the same day. If you need a respiratory consultant, the GP can arrange a specialist referral. Allergy testing can help when symptoms follow pets, pollen or dust, and our guide to choosing an allergy test explains the options.

If you have no urgent symptoms and want a baseline check of your lungs, private lung screening starts at £395 for a consultation, examination, spirometry, a chest X-ray and an in-person review of the results. If a chest infection is part of the picture, see our guide to chest infections.