Understanding what you are actually allergic to is the first step towards lasting relief. Allergies affect an estimated 18 million adults across the UK, and around 44 per cent of adults live with at least one allergic condition. This guide covers every major indoor and outdoor allergen found in British homes, from grass pollen and tree pollen to dust mites, pet dander and mould spores. For each, you will find the typical season, common symptoms, particle sizes and practical, non-medical steps to lower your exposure. It is written as general reference information and is not a substitute for advice from your GP, pharmacist or an allergy specialist.
Allergies in the UK: the bigger picture
Allergic conditions have risen sharply over recent decades, and the UK now has some of the highest rates in the world. The scale of the issue is often underestimated because symptoms are shared across many different triggers.
| Measure | Approximate figure |
|---|---|
| UK adults living with allergies | 18 million |
| Adults with at least one allergy | 44 per cent |
| Estimated annual cost to the NHS | Around £1 billion |
| Increase in allergy prevalence since 1990 | Roughly 50 per cent |
Allergens are broadly divided into two groups: outdoor allergens, which are mostly seasonal and driven by pollen, and indoor allergens, which tend to cause symptoms all year round. Many people are sensitive to more than one, which is why symptoms can persist even outside the classic hay fever season.
Outdoor allergens: pollen and the hay fever season
Pollen allergy, commonly called hay fever or allergic rhinitis, affects more than 10 million UK adults. The season is longer than many realise because different plants release pollen at different times. Understanding which pollen affects you helps you plan ahead and reduce exposure.
Grass pollen
- Season: May to July, peaking in June
- Prevalence: Around 95 per cent of hay fever sufferers react to it
- Common symptoms: Sneezing, itchy eyes, runny nose and congestion
- Notes: The most common trigger in the UK. Symptoms are often worst in the early morning and evening, when pollen settles closer to the ground.
Tree pollen
- Season: March to May
- Prevalence: Around 25 per cent of hay fever sufferers
- Common symptoms: Itchy throat, watery eyes and facial pressure
- Notes: Birch, oak, ash and plane trees are frequent culprits. Tree pollen usually starts the season before grass pollen peaks.
Weed pollen
- Season: June to September
- Prevalence: Around 15 per cent of hay fever sufferers
- Common symptoms: Nasal congestion, itchy skin and headaches
- Notes: Nettle, dock and mugwort are common UK weed allergens and can extend the allergy season well into late summer.
Indoor allergens: year-round triggers
Indoor allergens can cause symptoms in every season. The UK's mild, damp climate and well-insulated homes create ideal conditions for dust mites and mould in particular. Because these triggers live inside, symptoms often continue through autumn and winter when pollen has faded.
Dust mites
- Season: Year-round, often peaking in autumn and winter
- Prevalence: Around 12 million UK adults affected
- Common symptoms: Morning sneezing, a stuffy nose, itchy eyes and coughing
- Notes: Microscopic creatures that live in bedding, carpets, curtains and upholstery. It is the protein in their waste, not the mite itself, that triggers reactions.
Pet dander
- Season: Year-round
- Prevalence: Around 10 to 20 per cent of the UK population
- Common symptoms: Wheezing, skin rashes, itchy eyes and a runny nose
- Notes: Proteins in skin flakes, saliva and urine cause the reaction. Cat allergy is roughly twice as common as dog allergy in the UK.
Mould spores
- Season: Autumn and winter, and any damp period
- Prevalence: Around 10 per cent of the UK population
- Common symptoms: Coughing, wheezing, skin irritation and sinus problems
- Notes: The UK's damp climate makes mould common in bathrooms, kitchens, basements and poorly ventilated rooms.
Allergen particle sizes and why they matter
Different allergens travel through the air as particles of very different sizes, measured in microns (one thousandth of a millimetre). Particle size determines how easily an allergen stays airborne and how effectively a filter can capture it.
| Allergen | Typical particle size |
|---|---|
| Grass pollen | 20 to 40 microns |
| Tree pollen | 15 to 30 microns |
| Mould spores | 2 to 10 microns |
| Dust mite particles | 1 to 10 microns |
| Pet dander | 0.5 to 10 microns |
Larger particles such as pollen settle quickly onto surfaces, while smaller particles like pet dander can remain suspended for hours. This is why regular cleaning, good ventilation and air filtration each play a role in reducing exposure.
Practical ways to reduce your exposure
You cannot eliminate allergens entirely, but you can lower the concentration in your home and daily routine. These steps are widely recommended by allergy organisations as general self-care measures.
- Track the pollen forecast: Check the Met Office pollen forecast and keep windows closed on high-count days, especially in the early morning and evening.
- Rinse pollen away: Shower and change clothes after being outdoors, and avoid drying washing outside during peak season.
- Manage humidity: Keep indoor humidity below about 50 per cent to discourage dust mites and mould. Use extractor fans and ventilate damp rooms.
- Wash bedding hot: Launder bedding weekly at 60 degrees Celsius to reduce dust mite populations.
- Reduce soft furnishings: Hard flooring, wipeable surfaces and washable covers hold fewer allergens than carpets and heavy curtains.
- Create pet-free zones: Keep pets out of bedrooms and off beds to limit dander where you sleep.
- Filter the air: A quality air filter can capture airborne pollen, dust mite debris, pet dander and mould spores, particularly overnight in the bedroom.
How air purifiers help with allergies
Air filtration is recommended by health authorities as one part of a wider allergy management strategy. A purifier fitted with a high-grade filter draws air through a dense media that traps airborne particles before they reach your airways. MERV-13 media is a practical choice for allergen control because it captures fine particles in the 1 to 10 micron range where most allergen debris sits.
The Luggable XL 7-Fan is designed for exactly this task. Independent testing shows a MERV-13 filter capturing around 93 per cent of fine particles, with a clean air delivery of up to 681 cubic metres per hour, enough to circulate the air in a typical bedroom several times an hour. It runs at under 35 decibels on its lower settings, quiet enough to leave on overnight, and costs approximately £2 per year to run. It was recognised as an Energy Star Most Efficient 2026 product.
Where a purifier makes the biggest difference
- The bedroom: You spend around eight hours a night here, so overnight filtration can noticeably reduce morning symptoms.
- Living spaces: High-traffic rooms accumulate pollen brought in on clothing and pet dander from soft furnishings.
- Damp-prone rooms: Filtration complements good ventilation in reducing mould spores.
When to seek professional advice
Self-care and exposure reduction help most people, but some symptoms warrant professional input. Speak to your pharmacist or GP if over-the-counter measures are not controlling your symptoms, if symptoms interfere with sleep or daily life, or if you experience wheezing, chest tightness or breathlessness. Allergy testing, arranged through your GP, can confirm exactly which allergens affect you and guide a more targeted plan. This guide is general reference information and does not replace personalised medical advice.
