Everything you need to know about hay fever – including how to treat it

Most of us are delighted when spring finally arrives, but for millions of hay fever sufferers, the warmer temperatures and longer days signal the start of their annual battle with symptoms. While for some people these can be relatively mild, for others they are completely debilitating. 

“Some are so badly affected that they can’t go outdoors, their eyes are swollen and they can’t see properly,” says Dr Adrian Morris, consultant allergist at the Surrey Allergy Clinic. “Their nose is all blocked up, and it looks like a cold or Covid, so no one wants to go near them. It can affect their sleep, ability to drive and ability to function normally.”  

Hay fever is common and increasing. According to Allergy UK, one in four adults in the UK are affected by hay fever, with the numbers trebling in the past 30 years. 

Climate change is undoubtedly a factor. Research by the UK’s chief pollen forecaster, Dr Beverley Adams-Groom, has shown that the pollen season – which typically lasts from May to September – is getting longer and that more high-count pollen days are occurring. 

“High temperatures allow pollen trees to get the nutrients and sun they need and this boosts seed and pollen production,” she says. “Grass pollen is arriving earlier, although high temperatures can exhaust it. Last summer the grass pollen fell off a cliff with the 40-degree temperatures, so we’re seeing various effects due to climate change.”

Read on to learn everything you need to know about hay fever and the best ways to manage symptoms. 

What exactly is hay fever?

Hay fever is a common allergy to pollen from grass, trees and weeds.  

From spring to autumn these plants release their pesky pollen into the air where winds carry the fine particles to other plants to fertilise them. 

The problem is that this fine pollen is also very effective at entering the nose, throat and eyes.  In some people, the proteins inside the pollen trigger the immune system to release histamines that then cause the nose, throat and eyes to become irritated, swollen and inflamed. 

Types of hay fever

Seasonal allergic rhinitis 

The medical term for hay fever is seasonal allergic rhinitis. This effectively means an allergy of the nose, which is seasonal because it responds to pollen outdoors at certain times of the year. 

“Technically the term hay fever derived from allergies to hay during the harvest,” says Dr Morris. “Allergic rhinitis is the umbrella term for the nose allergy and that can also refer to allergies to pets, dust and mould inside the house that can occur year-round.”

Seasonal allergic rhinitis is at its worst when pollen from trees, grass and weeds in the air is highest, between mid to late March and September. 

Perennial allergic rhinitis

Perennial allergic rhinitis refers to symptoms that occur year-round regardless of the time of year. This type of allergic rhinitis is usually caused by triggers in the house that are present all the time like pets, dust, mould and cockroach droppings. 

What are the symptoms of hay fever? 

Common symptoms include: 

• Persistent sneezing
• A runny or stuffy nose, which can lead to difficulty breathing
• Itchy, watery and red eyes
• Itching in the throat or ears
• Sore throat
• Coughing
• Headaches
• Fatigue and irritability

Severe symptoms can also include: 

• Body aches
• Wheezing
• Shortness of breath
• Asthmatic wheezing
• Difficulty sleeping
• Itchy, red and watery eyes which can cause discomfort and sensitivity to light.

Many of the symptoms of hay fever are similar to a cold, so it can sometimes be tricky to tell the difference. 

“With hay fever, you won’t have a fever and when you have a cold you’re more likely to feel ill with body aches,” says Dr Morris. “Hay fever mucus is also clear, whereas with a cold it is more likely to be green or yellow.”

Hay fever can also trigger a strange symptom known as pollen food syndrome. The protein in the pollen triggers an itchy response in your mouth to certain raw foods including apples, peaches, cherries and carrots if you’re allergic to tree pollen. People allergic to grass pollen can find they get a reaction to raw melon, watermelon and potatoes. 

What triggers hay fever?

It’s important to work out what your triggers are so that you can do your best to avoid or minimise your exposure and reduce your symptoms. 

Triggers are usually pollen from trees, grass and weeds that are spread by wind. Fungus found on trees and leaves can also be a trigger. 

Dr Adams-Groom, who leads the team that works with the Met Office to provide the UK’s pollen forecast, says pollen can also become more potent in cities by interacting with pollution and high levels of CO2. 

“Airborne pollution such as ozone and diesel can interact with the pollen and enhance the allergenicity of it,” she says.

Although pollen tends to be more potent in the countryside, which has more trees and grass, it can travel long distances into the city suburbs. Pollen can also get trapped between buildings and the urban heat effect can mean it’s hotter and pollen is around for longer periods of the day. 

When do people usually get hay fever?

Hay fever sufferers can get symptoms at any time from mid-March to the autumn, depending on which pollen they are allergic to. 

The main tree season begins in March, although in February the alder tree begins to pollinate.  Alder trees don’t affect many people, but can play a role in “priming” people who suffer from birch tree allergies, says Dr Adams-Groom.

Birch pollen affects between 25 and 35 per cent of hay fever sufferers, and people begin to get symptoms when birch trees release their pollen from mid to late March. 

“Birch trees are very popular in the UK, they grow quickly and they’re pretty, but they’re a major source of pollen allergens for sufferers,” says Dr Morris. “March is the main tree month, sometimes the season starts earlier, sometimes later, you know it’s coming when you see all the catkins on the birch trees.”  

Oak tree pollen comes a little later, in April and May, and affects around 20 per cent of hay fever sufferers. 

Many charities and campaigners are calling for local councils to choose different, less allergenic trees when they are planting. In some areas in Germany and Denmark, birch trees are no longer planted. 

That said, the worst offender is grass pollen, which affects 95 per cent of hay fever sufferers. The season starts a bit later in May and lasts until July. 

Grass pollen doesn’t usually come from your garden lawn if it’s regularly mowed, but from flowering grasses that grow along verges or in meadows.

“Grass pollen is a big problem in the UK, the weather is a very conducive combination of rain and sunshine which causes them to pollinate madly and levels can get very high. The problem isn’t nearly as bad in France and Italy,” says Dr Morris. 

Around 20 per cent of hay fever sufferers are also allergic to weed pollens, including nettles and docks, and their season stretches from June to early autumn.

When are ‘pollen bombs’ likely to happen? 

“Pollen bomb” is not a term recognised by the experts, but it’s a handy way to describe those days when pollen counts spike extremely high. This is usually on warm days when high temperatures cause them to climb steeply.

“They often occur on the May bank holiday, just as lots of people are out and about in the parks,” says Dr Morris. “The worst times are around 11am and 6pm. A massive amount of pollen is released early in the morning, then as the day heats it rises and is at nose level around 11am. Then as the day gets hotter it rises high into the atmosphere. 

“When it cools down the pollen falls back to the earth and arrives at nose level around 6pm, just as people are beginning to think about firing up the barbecue.” 

Sometimes rain can improve the situation by washing the pollen away, although thunderstorms can make things worse by dispersing pollen and breaking it up and making it even finer.

Diagnosis and testing 

Many people with hay fever can work out what is triggering their symptoms by when and where they get symptoms. 

If they can’t, then skin prick testing (SPT) is sometimes used, where pollen is placed onto the skin, and if people are allergic then itchy red bumps appear. 

Blood tests are also used – samples are analysed to give a comprehensive analysis of specific antibodies produced in response to common allergens. 

If you’re considering immunotherapy or desensitising treatment you’ll need to be tested to ensure the allergen is correct. 

Treatments for hay fever

The first-line treatment for hay fever allergies is antihistamines. There are many different types, but they’re usually divided into antihistamines which make you feel sleepy like Piriton, and non-drowsy antihistamines like Clarityn. 

“These can work very well, especially in combination with a steroid nasal spray which dampens down the response in the nose,” says Dr Morris. 

You can also use antihistamine eye drops if your eyes are badly affected.

Yet for many people, the combination of antihistamines and steroid nose sprays doesn’t work, so for those with severe symptoms your GP might refer you for immunotherapy or you can access this privately. 

Immunotherapy works by giving small amounts of pollen to hay fever sufferers for three years, and gradually increasing the dose to desensitise them. 

“In my experience, immunotherapy is very effective,” says Dr Morris. “You start a couple of months before the pollen season begins so that they are primed, and over time it reduces their need for medication. It is expensive if you’re accessing it privately – the prescription costs around £100 a month – but the tablets we give them are getting better and better.” 

Some research in Canada has also pointed to Botox as a useful treatment for people whose symptoms don’t respond to other treatments. This is only available privately, however. 

Emerging new research also highlights the role of the nasal microbiome, with a study published last year in the journal Nature Microbiology showing that hay fever sufferers had a much narrower range of bacteria in their noses. In 2022, a study led by scientists at the National Institute of Integrative Medicine, in Melbourne, Australia, gave the probiotic formula NC-Seasonal-Biotic to hay fever sufferers.

They found that it significantly reduced symptoms, compared with a placebo group. After 10 to 12 weeks, the volunteers’ noses ran less and their eyes itched less. They even slept better and felt less irritable.

Margaret Kelman, acting head of clinical services at Allergy UK, says results of clinical trials into the use of probiotics alongside medication to improve hay fever symptoms are “encouraging”. However, she says more research is needed on which particular strains of probiotics are most useful for which symptoms. “We still need to understand how best to administer them, when to start taking them and for how long to deliver maximum benefit,” she notes.

Managing your hay fever symptoms

There are many things you can try to help prevent and reduce the severity of hay fever symptoms. Here are some of the strategies that experts recommend.

• Wear wrap-around sunglasses on sunny days, they can act as a barrier to pollen getting in your eyes.
• Smearing Vaseline around your nostrils with a cotton-wool bud can help stop pollen from getting into your nose.
• Nasal saline washes involve rinsing the nasal cavity with salt water. They can help to thin mucus and rinse away allergens and can be bought in most pharmacies.
• After being outside, pollen can be trapped in your hair and on your clothes, so wash your hair and change your clothes when you get home.
• Try a face mask like the ones from the Covid days, as they do filter out some of the pollen particles on high-count days.
• Buy an air purifier for your home, they filter pollen that might have blown into your bedroom, causing symptoms overnight.
• Try a nasal filter. This is a small device that sits just inside the nostrils and prevents pollen from getting into the nose. Studies have shown that these can be effective for some people.
• Keep an eye on the pollen forecast from the Met Office so you can avoid high-count days. There are also plenty of apps which allow you to track your allergies, some have live pollen maps.
• Don’t dry clothes outside, they could get pollen on them.

Hay fever and asthma 

Hay fever and asthma are closely connected – people who have asthma often have hay fever and hay fever symptoms can also cause people to develop seasonal asthma or worsen the symptoms of those who have asthma. 

“There is often a link between them,” says Dr Morris. “They tend to follow each other, so if you had eczema and asthma as a child you often go on to develop hay fever also. Some people who don’t usually get asthma get a tight chest and wheezing in the pollen season, known as hay fever asthma, and may need to use an inhaler.”

For more information contact Allergy UK; allergyuk.org