Hay fever - Diagnosing hay fever

Your GP should be able to diagnose hay fever from a description of your symptoms. In some cases, you may be referred for allergy testing.

A diagnosis for hay fever would usually only be required:

if your symptoms were particularly severe
the pattern of symptoms was unusual, such as having symptoms during the winter or while indoors
you experienced complications of hay fever

If possible, keep a diary of what times of the day or year you experience your symptoms, as this can help with the diagnosis.

Allergy testing

Your GP may refer you to an immunologist for an allergy test if you have hay fever symptoms all year round (persistent allergic rhinitis), or symptoms that are not responding to treatment. Other substances could be causing your allergy, such as house-dust mites, animals or certain foods.

The two main allergy tests are:

a skin prick test
a blood test

Skin prick test

An immunologist will place the allergen on your arm and prick the surface of your skin with a needle. This will introduce the allergen to your blood stream and, if you are allergic to it, you should have a reaction.

If your skin starts to go red around where it was pricked, swells up or becomes itchy, this could be an allergic reaction and would confirm that you have hay fever.

A skin prick test may not be suitable if:

you are on certain medications, for example antihistamines, which will stop you having an allergic reaction
you have significant eczema, as your skin may already be red or itchy, so an allergic reaction will not be noticeable

In this case, a blood test may be necessary to confirm your diagnosis (see below).

The use of commercial allergy testing kits is not recommended. The testing is often of a lower standard than that provided by the NHS or accredited private clinics. Also, it is important that the results of the test are interpreted by a qualified professional who has detailed knowledge of your symptoms and medical history.

Blood test

A sample of blood will be taken from a vein in your arm and tested for the presence of the Immunoglobulin E (IgE) antibody.

If you have hay fever, your body produces this antibody when it comes into contact with pollen. If your blood test is positive for IgE, this may confirm that you have hay fever.

Allergen: An allergen is a substance that reacts with the body's immune system and causes an allergic reaction, for example pollen.
Allergy: Allergy is the term used to describe an adverse (bad) reaction that the body has to a particular substance.
Antibodies: Antibodies are your body's natural defence against any foreign antigens that enter your blood. An antibody is a protein that is produced by the body to neutralise or destroy disease-carrying organisms and toxins.
Blood: Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.