Find out how an allergy to pollen can affect your asthma, and what you can do to manage it

Hay fever is dangerous for people with asthma  

  • It causes your already swollen airways to swell up even more, leaving you fighting for breath
  • It makes your already sensitive airways more likely to react to other triggers like dust or pollution
  • If hay fever combines with a cold, the added extra inflammation can result in big problems

Cold or hay fever? Spot the difference  

If your eyes/throat/nose and even mouth are itching, it’s more likely to be hay fever. If your nose is streaming clear snot, that’s another sign.

How to treat a ‘cold’ that might be early hay fever

Wondering what’s causing your itchy, snotty cold symptoms and runny eyes? There’s tree pollen around right now and many people with asthma are telling us they’re already getting hay fever symptoms.

Hay fever can trigger a potentially life-threatening asthma attack, so take these precautions to reduce your risk of an asthma attack caused by pollen:

  1. Carry your reliever inhaler with you at all times
  2. Take your preventer inhaler as prescribed – this dampens down the inflammation in your airways and reduces your risk of an attack
  3.  Treat the hay fever symptoms with antihistamines and antihistamine or steroid nasal spray. Different treatments work for different people - your pharmacist can help you find the right treatment for you. See our hay fever treatments page for detailed advice on treating hay fever and asthma.
  4. See your GP urgently if your symptoms are getting worse, or if you’re using your reliever inhaler three or more times a week.   

Get set for high pollen season

If you regularly suffer from hay fever, start taking antihistamines up to four weeks before your hay fever usually starts – changing weather means that it’s hard to predict exactly when pollen will be released. If you usually take a nasal spray too, remember it takes up to a week to start working, so again, take it before your personal pollen trigger is released.

How do you know if pollen is your trigger?

Keeping a diary can help you notice if pollen is a trigger for your asthma symptoms. If, for example, you get symptoms after you’ve been in the park, or the garden, at certain times of the year, it could mean you have a pollen allergy.  

Noting the daily pollen count can also help you spot whether or not your allergy symptoms are worse when the count is high.

Your GP can work out whether or not you have hay fever by talking to you about your symptoms. They may prescribe some hay fever medicines to see if they help. Or they may refer you for a skin prick test and/or blood test to confirm whether or not you're allergic to pollen and to identify which pollen(s) you're allergic to.

How does hay fever increase your risk of asthma symptoms or an asthma attack?

Hay fever - particularly from grass pollen - can be a risk to people with asthma. Studies show that when there are higher concentrations of grass pollen in the air, more adults are admitted to hospital because of their asthma.

For most people pollen is harmless. But if you have an allergy to pollen your immune system overeacts and produces histamine. It's the histamine that irritates your nose, eyes and throat,  giving you typical hay fever symptoms.

For many people with asthma, this release of histamine when they have hay fever makes asthma symptoms worse.

Having a blocked nose can also be a problem for your asthma. Usually when you breathe in, you breathe in through your nose so the air is warmed up and moistenend before it gets to your airways. But when your nose is blocked you breathe in through your mouth, so the air you're inhaling is colder and drier. 

In some people with asthma, the airways are sensitive to this and react. This can lead to asthma symptoms, such as coughing, wheezing, a shortness of breath and tightness in the chest.

Download an asthma action plan

Who is most likely to have a pollen allergy?

Hay fever, caused by an allergy to pollen, is very common. It affects about one in five people in the UK. Teenagers and young adults are most commonly affected, although it can develop at any age. Hay fever is more common in boys than in girls; in adults, men and women are equally affected.

Hay fever and asthma are closely linked - 62% of people with asthma tell us their asthma symptoms are triggered by pollen.

If you have asthma and hay fever, your GP or asthma nurse may add hay fever treatments to your written asthma action plan.

Symptoms of hay fever

The most common symptoms of hay fever are:

  • blocked nose
  • watery, runny nose
  • sneezing
  • itchy nose
  • watery eyes

Other symptoms include:

  • headaches
  • reduced sense of smell
  • itchy eyes
  • disrupted sleep, tiredness and irritability
  • earache

When is pollen most likely to affect you?

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. About 20% of people with hay fever are allergic to birch tree pollen. The pollen from oak trees and plane trees also affects lots of people.

Grass pollens are the most common cause of hay fever and usually affect people in May, June and July.

Weed pollens (such as nettles) usually release pollen from early spring to early autumn.

How do you know which pollen you're allergic to? 

Your GP might refer you for a skin prick test and/or blood test, to confirm which type or types of pollen set off your hay fever. But it's also a good idea to take a note of when you have symptoms.

For example, if your symptoms start as early as January or February and continue until late March, it may be that you're allergic to early flowering trees, such as the hazel and alder.

Bear in mind, though, that the season and severity of each type of pollen changes each year according to that year's weather conditions.

It's possible to be allergic to more than one type of pollen - and you may also be allergic to the spores from moulds or fungi.

Does the weather affect hay fever symptoms?

The weather can make a difference to hay fever symptoms. For example:

On hot, sunny days, more pollen is released so the pollen count tends to be higher.

During a thunderstorm when it's very humid, high levels of pollen can be swept up high into the air. Moisture breaks the pollen into much smaller pieces. As the pollen settles back down, these smaller pieces can be breathed into the smaller airways of the lungs. This irritates the airways and can trigger asthma symptoms.

Does poor air quality affect hay fever symptoms?

Air pollution can peak during warm, dry days. The combination of warm, dry weather and poor air quality creates a smog which traps pollen, preventing it from escaping into the upper atmosphere. This can make hay fever symptoms worse and is sometimes known as 'grey fever.' 

There's also some evidence that pollution can make pollen 'stickier', creating 'super pollen' particles which are harder to remove from the airways.

People living in towns and cities should take extra care as they're at a greater risk from what's known as 'super pollen'. This is where pollen particles combine with pollution. If you know that pollen or pollution triggers your asthma symptoms, check forecasts for your area and carry your reliever inhaler with you at all times."

  Dr Andy Whittamore, Asthma UK in-house GP

What's the best way to cut the risk of pollen making your asthma worse? 

It's difficult to avoid pollen completely, but there are a number of ways you can reduce the risk of pollen affecting you.

1. Take the asthma attack risk checker.  Around 75% of emergency hospital admissions for asthma could be prevented with better management and support. The risk checker will reveal your risk of having an asthma attack and tell you how you can reduce it.

2. Manage your asthma well. This is the best way to reduce the risk of pollen making your asthma symptoms worse. You can do this by:

3. Take medicines for hay fever. Research shows that anyone with asthma who also has hay fever can significantly lower their risk of going to A&E if they treat their hay fever. This could include nasal steroids, anti-histamines or anti-inflammatory eye-drops.

4. Try these practical tips from people with asthma

  • Keep doors and windows closed when you're indoors and the pollen count's high.
  • Wear wraparound sunglasses to stop pollen getting in your eyes when you're outside.
  • Change your clothes and have a shower when you've been outside.
  • Don't cut the grass and avoid walking in grassy areas if you're allergic to grass pollen.
  • If possible, avoid drying your clothes outside as pollen will stick to them.
  • Remember that pollen counts are generally higher in the early morning and late afternoon/early evening, so it may be better to avoid being outside at these times if possible.
  • Dust with a damp cloth and vacuum with a HEPA (high-efficiency particle arresting) filter regularly.
  • Don't smoke or let other people smoke around you because it can make hay fever (and asthma) symptoms worse.
  • Alcohol can increase your sensitivity to pollen so it may be worth avoiding it when the pollen count is high and/or your symptoms are worse.
  • If possible, don't go outside before, during or just after a thunderstorm.
  • Keep an eye on air pollution levels on the Defra website and, if possible, avoid going out when air pollution levels are particularly high.
  • When you're booking a holiday, remember that the pollen count is likely to be lower in locations by the sea.
  • If you're going abroad, check the local pollen information and forecast before travelling. 

 5. Ask for support or advice 

If you have any questions about how you can manage your asthma better, speak to your GP, asthma nurse or pharmacist. You can also call the Asthma UK Helpline on 0300 222 5800 (Mon – Fri; 9am – 5pm) and speak to our asthma nurse specialists.


Last updated February 2018

Next review due May 2019