Hay fever
Hay fever (allergic rhinitis) is a common allergic condition that affects up to 1 in 5 people in the UK. It is caused by an allergic reaction to pollen from grasses, trees or weeds.
Symptoms typically occur during the pollen season (spring and summer) and include sneezing, a runny or blocked nose, itchy and watering eyes, and an itchy throat, mouth and ears.
Allergy blood tests can identify specific pollen allergens triggering the immune response by measuring IgE antibody levels. This helps distinguish between grass, tree and weed pollen allergies, which can be useful for timing avoidance strategies and considering immunotherapy.
Management options include antihistamines, nasal corticosteroid sprays and allergen avoidance. For persistent or severe cases, allergen immunotherapy (desensitisation) may be considered.
Causes of Hay fever
Hay fever is caused by an allergic reaction to pollen. When pollen particles are inhaled or come into contact with the eyes, the immune system of a sensitised individual produces IgE antibodies that trigger the release of histamine and other inflammatory chemicals.
The type of pollen responsible varies by season:
- Tree pollen (such as birch, oak and ash) is the main trigger from late February to May
- Grass pollen is the most common trigger overall, peaking from May to July
- Weed pollen (such as mugwort and ragweed) is more prominent from June to September
Risk factors for developing hay fever include a family history of allergies (atopy), having asthma or eczema, and being exposed to tobacco smoke in childhood. Hay fever often begins in childhood or adolescence but can develop at any age.
Tests that can help check this condition
Learn more on the official NHS page .
Medical review
Dr. Shahzaib Ahmad MBBS, BSc, MRCP, FRCA, FFICM
Clinical Supervisor - Vitall|GMC 7495062|Profile
Reviewed on 22/05/2026
Next review due 22/05/2027
Review focus: Blood biomarkers, laboratory testing methodology, and biochemical interpretation.
