Hay fever and asthma sufferers may have noticed symptoms get worse in recent weeks as pollen levels across the UK rise.
The hay fever season starts at different times across the UK and the type of pollen in the air will differ according to the time of year.
There are around 30 different types of pollen that can cause hay fever and it is possible to be allergic to more than one, so the onset of symptoms may vary depending on your allergy.
When does hay fever season start?
In the UK, hay fever is usually worse between late March and September, particularly when the weather is warm, humid and windy as the pollen count is at its highest.
The type of pollen in the air differs depending on the time of year, with tree pollen occurring first from late March through to mid-May.
This is followed by grass pollen which lasts from mid-May until July, and weed pollen comes later from the end of June to September.
Grass pollen also has a second peak which tends to occur in the first two weeks of July before levels slowly decline.
What are the factors behind pollen levels?
Pollen levels are very much dependent on the weather conditions during spring and early summer, with lower temperatures causing less pollen to be produced. Spring rainfall is also key, as a dry season reduces the amount of pollen production.
The start of the hay fever season is also dependent on where you live, according to the Met Office. Those who live in the north of the UK will see a later start and a shorter season as there is generally less pollen. Urban areas have a lower pollen count than in the countryside, while inland areas have higher counts than around the coast.
What pollen allergy is most common?
Around 30 different types of pollen can cause hay fever and it is possible to be allergic to more than one, meaning symptoms could be worse at different times of the year.
Most people are allergic to grass pollen which is most common from late spring to early summer. Other pollen types can also trigger symptoms, with tree pollen - released during spring - affecting around 25% of people.
Symptoms usually occur when the pollen count (the number of pollen grains in one cubic metre of air) exceeds 50 and will typically be worst in the early evening when the count is at its highest.
Around two in every 10 people suffer with pollen allergies and it is most common among those who suffer from asthma or eczema, or have a family history of allergies.
The NHS says the most common symptoms of hay fever include:
- sneezing and coughing
- a runny or blocked nose
- itchy, red or watery eyes
- itchy throat, mouth, nose and ears
- loss of smell
- pain around your temples and forehead
- feeling tired
If you have asthma you may also have a tight feeling in your chest, be short of breath, or wheeze and cough.
Hay fever symptoms can last for weeks or months, unlike a cold which usually goes away after one to two weeks.
Are there any treatments?
There is currently no cure for hay fever and it cannot be prevented. However it is possible to relieve symptoms with some simple treatments and home remedies. These include:
- putting Vaseline under your nose to trap pollen
- wearing wraparound sunglasses to stop pollen getting into your eyes
- showering and changing your clothes after being outdoors
- staying indoors when possible
- keeping windows and doors shut
- vacuuming regularly and dusting with a damp cloth
- buying a pollen filter for the air vents in your car and a vacuum cleaner with a special HEPA filter
A pharmacist may also be able to give advice on the best treatments and may recommend antihistamine tablets, drops or nasal sprays to help ease itchy and watery eyes, sneezing, and a blocked nose.
You should avoid cutting or walking on grass to reduce the risk of making symptoms worse. It is also advisable to not keep fresh flowers in the house, avoid drying clothes outside and not to smoke or be around smoke.