Different causes of hay fever

Reviewed by our clinical team

Hay fever is a very common allergic condition that causes symptoms during the spring, summer and early autumn, particularly on warm and humid days. Symptoms can include itchy, watery eyes, a runny or blocked nose, sneezing and coughing.

If you have hay fever, you’ll know that it’s caused by an allergy to pollen. What you might not be aware of is that there are many different types of pollen, and each type is released at a different time of year.

Getting a better understanding of which types of pollen cause hay fever symptoms may help you manage your symptoms better.

What causes hay fever?

Hay fever, is a type of allergic rhinitis, an allergic condition that is connected to the immune system. When a person with hay fever is exposed to pollen, their immune system reacts as though the pollen is a harmful substance, and releases chemicals to attack it, including histamine. 

Histamine causes the blood vessels to expand and the skin to swell, which leads to the distinctive symptoms of hay fever. These symptoms tend to affect the nose, mouth, throat, and eyes.

What types of pollen cause hay fever?

Pollen is a fine powder released by plants to fertilise other plants of the same species. It is carried in the air, and is spread particularly quickly on warm and windy days.

If you have hay fever you may have an allergy to one or more of these types of pollen:

• Grass 
• Hazel 
• Yew 
• Elm 
• Alder 
• Willow 
• Ash 
• Poplar 
• Birch 
• Oak 
• Pine 
• Oil seed rape 
• Plane 
• Dock 
• Nettle 
• Lime 
• Plantain 
• Mugwort

There are also lots of other types plants that flower or have cones that can release pollen.

These plants and trees all release their pollen at different times, and over different lengths of time.

• Grass pollen is released between April and September, peaking in June.  
• Trees like hazel, yew, elm, alder, willow and ash release their pollen between January and April, with a peak period in February and March. 
• Trees like poplar, birch, oak and pine release their pollen in late spring, between March and June. 
• Weeds like dock, nettle and mugwort release their pollen in the later summer months.

It may not be easy to work exactly which type of pollen is causing your hay fever symptoms. However, if you keep a note of when during the year your symptoms occur, and whereabouts your symptoms started, you may be able to narrow it down.

For more guidance about when different trees and plants release their pollen, consult this leaflet from Allergy UK.

How can I avoid pollen?

It’s not always easy to avoid pollen, especially on warm, humid and windy days. However, there are some steps you can take to reduce your exposure:

• Get into the habit of checking the pollen count. You can do this by visiting the Met Office website and searching for your region. The system will tell you whether the pollen count is Very High, High, Moderate or Low. It will also tell you which types of pollen are widespread that day. 
• Stay indoors with windows and doors shut on high pollen days. 
• Don’t dry laundry outdoors. 
• Vacuum your home regularly using a cleaner with a HEPA filter, and dust surfaces with a damp cloth.

If you do have to go outside when the pollen count is high, do the following: 

• Put petroleum jelly (vaseline) around your nostrils and wear wraparound sunglasses.  
• Carry allergy medication like antihistamines in case symptoms flare up. 
• Try to avoid wooded or grassy areas where there’s likely to be more pollen. 
• When you get home, change your clothes and take a shower.

What can cause allergic symptoms in the autumn and winter?

Grass, trees and plants release their pollen between January and September. If you’re experiencing symptoms similar to hay fever during the autumn and winter, the cause will be an allergy to something else, like mould spores, dust mites, or animal dander. 

If you can work out what is causing your allergic symptoms, you can take steps to avoid it. To learn more, consult this guide from the NHS. 

Manage your hay fever symptoms with Online Doctor

Our doctors can prescribe Telfast, an effective allergy tablet for people with hay fever.

Or you can visit LloydsPharmacy for over the counter hay fever tablets (like Piriton), sprays and drops. 

Visit our online allergy clinic to find out more.

References

https://www.nhs.uk/conditions/hay-fever/
https://www.mayoclinic.org/diseases-conditions/hay-fever/symptoms-causes/syc-20373039
https://www.nhs.uk/conditions/antihistamines/
https://www.allergyuk.org/assets/000/000/921/13013_-_Four_Seasons_Booklet_individual_pages_original.pdf?1493980384