What causes hay fever?
Hay fever is caused when the body makes allergic antibodies (IgE) to certain substances, such as pollen, house dust mites or mould, which are known as allergens.
Grass pollen is the most common allergen (May to July), but tree (February to June) and weed (June to September) pollens can also cause the allergic reaction we know as hay fever. In perennial allergic rhinitis the symptoms continue all year round and usually relate to indoor allergens, such as house dust mites, pets, including birds, or moulds.
What are the symptoms of hay fever?
- Itchy eyes/ throat
- Sneezing, blocked/runny nose
- Watering, red eyes (allergic conjunctivitis)
- Headaches, blocked sinuses
- Shortness of breath
- Tiredness
- The sensation of mucus running down the back of the throat, which can also be a symptom, is called ‘post-nasal drip’.
These symptoms may become more severe when the pollen count is high.
What hay fever medications could I use?
The treatments prescribed for allergy control the symptoms and reactions; they do not cure the condition. Find out more about treatments from our Factsheet.
Antihistamines are probably the best known type of allergy medication, and most are readily available from a pharmacy without prescription. However, there are a number of different types of antihistamines; some have been used for many years, some are improvements on old drugs, and new antihistamines are being developed all the time. While antihistamines used to have a reputation for making people drowsy, more modern antihistamines only occasionally have those side effects. These can be used on their own for mild hay fever or in combination with an intranasal steroid spray for moderate to severe symptoms You can find out more about how antihistamines work on our ‘Allergy Medications’ Factsheet.