Hay Fever: Causes, Symptoms & Treatments

In this ultimate guide to hay fever, our experts explain the science behind the various causes and types of hay fever and which treatments can help with rapidly alleviating common hay fever symptoms.

Updated: Monday 10 June 2024


man and woman stretching their legs outdoors

Hay fever is estimated to affect more than 10 million people in the UK[1], typically when the pollen count increases during the warmer and sunnier months of spring and summer.

Also referred to as allergic rhinitis, hay fever describes a group of symptoms that predominantly affect the nose and eyes and can be alleviated through certain lifestyle habits and the use of hay fever treatments.

This guide comprehensively covers the causes of hay fever and how its symptoms can be alleviated, based on the current understanding of this condition and the latest scientific research.

What is hay fever?

Hay fever is a common allergic condition triggered by an immune response to allergens such as pollen.

Hay fever symptoms are typically experienced when the body’s immune system mistakenly identifies allergens as being harmful and produces antibodies in response[2].

These antibodies subsequently send a signal to widen the blood vessels and ramp up the production of inflammatory chemicals such as histamine.

Hay fever may be broadly categorised as:

  • Seasonal hay fever, which is typically caused by allergic sensitivity to airborne pollen, mould spores, and grass. Seasonal hay fever is most likely to occur in the months between the start of spring and the start of autumn, as this is when the pollen count typically increases each year.
  • Perennial hay fever, which is usually caused by dust mites, pet hair and mould. As the name suggests, perennial hay fever can occur all year round.

What are the symptoms of hay fever?

The most common symptoms of hay fever are:

  • A runny or blocked nose
  • Itchy, red or watery eyes
  • An itchy throat or mouth
  • Sneezing and coughing
  • Headaches
  • Fatigue, which can occur as a result of a lack of sleep and/or poor sleep quality due to common hay fever symptoms such as nasal blockages

The frequency, duration, and severity of hay fever symptoms depend on the individual’s pollen immunity and the current levels of pollen in the air (known as the ‘pollen count’).

The daily pollen count may be tracked using our pollen count forecast tool which accounts for weather patterns and annual pollen production from 15 species of plants.

What causes hay fever?

Hay fever is primarily caused by allergens such as:

  • Pollen
  • Mould or fungi
  • Dander or pet fur
  • Dust mites
  • Cigarette smoke
  • Perfume

Hay fever can also be caused by certain genetic factors. For instance, if an individual’s parents have allergies, then they are more likely to experience allergy symptoms as well, including hay fever.

This is because inherited genes can predispose individuals to an overreactive immune system, particularly through certain genes that regulate the production and response of immunoglobulin E (IgE), a key antibody in allergic reactions[3].

In some cases, the children of parents with allergy-related diseases can be more likely to develop hay fever, even if the parents do not suffer from hay fever.

It is also worth noting that other respiratory and skin conditions like asthma and eczema, which are also often hereditary, do not increase the risk of developing hay fever.

Recommended reading: How to manage hay fever symptoms whilst outdoors

What makes hay fever symptoms worse?

There are a number of factors that can potentially aggravate hay fever symptoms, including those that may not have caused the symptoms to begin with.

Try to reduce or eliminate exposure to these triggers:

  • Cigarette or wood smoke
  • Strong odours, like hair spray or perfume
  • Air fresheners
  • Exhaust fumes and other similar air pollutants
  • Changes in air temperature and humidity

How to prevent hay fever symptoms

Experiencing hay fever can feel like an inevitability at certain times of the year. However, it pays to be aware of the barriers you can put between yourself and the potentially triggering irritants.

These include:

  • Keeping the windows shut throughout hay fever season to prevent pollen from coming inside. If you wish to keep your home cool on hot days, it can be worth using a fan or air conditioning unit rather than opening the window.
  • Wearing sunglasses when outdoors as this can reduce the probability of allergens such as pollen landing on the surface of the eyes and causing irritation.
  • Using a dehumidifier to prevent mould from growing indoors, especially if the windows are closed as it would reduce indoor ventilation.
  • Washing your hands thoroughly after petting animals to avoid transferring pet dander (such as fur) to your clothes or skin, as this can trigger hay fever symptoms.

How to treat hay fever symptoms

Antihistamine tablets

Antihistamine tablets disrupt the production of histamines, which the body produces to fight what it thinks are harmful infections (mistakenly, in the case of allergies). During hay fever season, antihistamine tablets can be taken once per day to provide relief for up to 24 hours.

Some of the most popular antihistamine tablets include:

  • Fexofenadine, which is one of the most effective non-drowsy antihistamines. It contains the active ingredient ‘fexofenadine hydrochloride’, which bocks the histamine receptors in the spinal cord, preventing common hay fever symptoms such as sneezing.
  • Telfast and Allevia), which also contain fexofenadine hydrochloride but are more expensive than Fexofenadine as they are branded medications (Fexofenadine is cheaper and produces identical effects to Telfast and Allevia).

Additional antihistamine tablets that can be considered include:

  • Cetirizine, which contains the active ingredient ‘cetirizine hydrochloride’ (this same active ingredient is also present in the more expensive branded hay fever treatment Piriteze).
  • Clarityn and Clarityn Rapide, both of which contain the active ingredient ‘Loratadine’, with Clarityn Rapide offering faster relief from hay fever symptoms than Clarityn.

Nasal sprays

Nasal spray treatments for hay fever typically contain active ingredients belonging to the corticosteroid family of medicines.

Corticosteroids reduce inflammation inside the nose, helping with breathing and reducing the common symptoms of sneezing, itching and a running nose.

Popular nasal sprays for hay fever include:

  • Mometasone Furoate, which contains the primary active ingredient 'mometasone furoate' (a corticosteroid).
  • Nasonex, which also contains mometasone furoate but is more expensive than Mometasone Furoate as it is a branded medication (Mometasone Furoate is cheaper and produces identical effects to Nasonex).

Additional nasal sprays to consider to relieve hay fever include:

  • Pirinase - a non-drowsy nasal spray that contains the corticosteroid ‘fluticasone propionate’.
  • Sterimar nasal spray - a non-corticosteroid nasal spray which contains a pure saline solution to help clean the nasal passages.

Eye drops

Eye drops provide rapid relief from itchy, red and/or watery eyes resulting from hay fever. Effective eye drops for hay fever include:

  • Sodium Cromoglicate - a treatment that contains the active ingredient ‘sodium cromoglicate’ which stabilises mast cells in the eyes to stop them from becoming itchy, red, or watery.
  • Opticrom eye drops - a branded (and therefore more expensive) version of Sodium Cromoglicate.

Buy hay fever treatments for fast delivery across the UK from Pharmica

At Pharmica, we offer a wide range of hay fever treatments that are clinically proven to help relieve common symptoms such as sneezing, nasal congestion, and itchy/watery eyes.

The hay fever treatments we provide are all sourced from MHRA-approved suppliers to guarantee quality, ensuring customers and patients can alleviate hay fever symptoms quickly and reliably.

Pharmica is rated 4.9/5 from more than 190,000 reviews and we have served over 1.3 million customers and patients. Browse our full range of treatments today.

  1. NHS. (2023). Hay Fever. Available at: https://www.nhsinform.scot/illnesses-and-conditions/immune-system/hay-fever. [Accessed: 4 June 2024].
  2. John Hopkins Medicine. (n.d.). Allergies and the Immune System. Available at: https://www.hopkinsmedicine.org/health/conditions-and-diseases/allergies-and-the-immune-system#:~:text=When%20a%20harmless%20substance%20such,itchy%20eyes%2C%20and%20other%20symptoms. [Accessed: 4 June 2024].
  3. Meng & Rosenwasser. (2010). Unravelling the genetic basis of asthma and allergic diseases. Allergy, Asthma and Immunology Research, 64(4), pp. 253-260. doi: https://doi.org/10.4168%2Faair.2010.2.4.215
Kamran Bell

Written by: Kamran Bell

Pharmacist・GPHC Number 2231070

Kamran graduated with a four-year master's degree in pharmacy from Aston University in 2021. He completed a pre-registration year at a community pharmacy before working there for a further year. At Pharmica, Kamran provides expert patient advice and addresses clinical questions to ensure the health and well-being of our patients.


Carolina Goncalves

Medically Reviewed by: Carolina Goncalves

Superintendent Pharmacist・GPHC Number 2088658

Carolina Goncalves is the Superintendent Pharmacist at Pharmica, where she ensures patients receive exceptional healthcare and support, as part of a seamless online pharmacy service.

With a comprehensive professional background spanning more than 13 years, Carolina has extensive experience supporting Men’s and Women’s health. Carolina is responsible for providing expert treatment advice to thousands of patients in areas such as Sexual Health, Erectile Dysfunction, Hair Loss, Weight Loss and Asthma.


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How To Manage Hay Fever Symptoms Whilst Outdoors
How To Manage Hay Fever Symptoms Whilst Outdoors