Hay fever is caused by pollens of specific seasonal plants and airborne chemicals and dust particles in people who are allergic to these substances. It is characterised by sneezing, runny nose and itching eyes. This seasonal allergic rhinitis is commonly known as 'hay fever', because it is most prevalent during haying season. It is particularly prevalent from late May to the end of June (in the Northern Hemisphere). However it is possible to suffer from hayfever throughout the year

Causes
The effect of hay fever can vary greatly: some people may only be mildly afflicted, whereas others may suffer greatly. Common symptoms include:

coughing
headache
itching nose, mouth, eyes, throat, skin, or any area exposed to the allergen.
runny nose (and occasionally nosebleeds)
impaired smell (and thus sensitivity to flavours)
sneezing
stuffy nose (nasal congestion)
watering eyes and/or plugged up ear canals.
sore throat
wheezing
cross-reactivity allergy to some fruits
conjunctivitis
fever
fatigue
flushing Symptoms
The history of the person's symptoms is important in diagnosing allergic rhinitis, including whether the symptoms vary according to time of day or the season, exposure to pets or other allergens, and diet changes.
Allergy testing may reveal the specific allergens the person is reacting to. Skin testing is the most common method of allergy testing. This may include intradermal, scratch, patch, or other tests. Less commonly, the suspected allergen is dissolved and dropped onto the lower eyelid as a means of testing for allergies. (This test should only be done by a physician, never the patient, since it can be harmful if done improperly.)
In some individuals who cannot undergo skin testing (as determined by the doctor), the RAST blood test may be helpful in determining specific allergen sensitivity.
Sufferers might also find that cross-reactivity occurs. There are many cross-reacting substances.

Signs and tests
Avoiding exposure to pollen is the best way to decrease allergic symptoms.

Remain indoors in the morning and evening when outdoor pollen levels are highest.
Wear face masks designed to filter out pollen if you must be outdoors.
Keep windows closed and use the air conditioner if possible in the house and car.
Do not dry clothes outdoors.
Avoid unnecessary exposure to other environmental irritants such as insect sprays, tobacco smoke, air pollution, and fresh tar or paint.
Avoid mowing the grass or doing other yard work, if possible. Avoid fields and large areas of grassland.
Regular hand- and face-washing removes pollen from areas where it is likely to enter the nose.
A small amount of petroleum jelly around the eyes and nostrils will stop some pollen from entering the areas that cause a reaction
Avoid bicycling or walking - instead use a method of confined transportation such as a car.
Wear sunglasses, which reduce the amount of pollen entering the eyes. Prevention
The goal of treatment is to reduce allergy symptoms caused by the inflammation of affected tissues. The best "treatment" is to avoid what causes your allergic symptoms in the first place.

Medication
Allergen immunotherapy is commonly used in patients suffering from allergic rhinitis, allergic asthma, or life threatening stinging insect allergy. This type of therapy has been found to potentially alter the course of all three of the above disorders. Allergen immunotherapy provides long-term relief of the symptoms associated with rhinitis and asthma.

Allergen immunotherapy
Eating locally produced unfiltered honey is believed by many to be a treatment for hayfever, supposedly by introducing manageable amounts of pollen to the body. Clinical studies have not provided any evidence for this belief.

Honey
It has been claimed that homeopathy provides relief free of side-effects. However, this is strongly disputed by the medical profession on the grounds that there is no valid evidence to support this claim. The list of suggested medication includes

arundo mauritanica
galphimia glauca
luffa Homeopathy
Therapeutic efficacy of complementary-alternative treatments for rhinitis and asthma is not supported by currently available evidence. to show that acupuncture is more effective than antihistamine drugs in treatment of hay fever. Complementary-alternative medicines such as acupuncture are extensively offered in the treatment of allergic rhinitis by non-physicians but evidence-based recommendations are lacking. The methodology of clinical trials with complementary-alternative medicine is frequently inadequate. Meta-analyses provides no clear evidence for the efficacy of acupuncture in rhinitis (or asthma). It is not possible to provide evidence-based recommendations for acupuncture or homeopathy in the treatment of allergic rhinitis.

Expectations
A case-control study found "symptomatic allergic rhinitis and rhinitis medication use are associated with a significantly increased risk of unexpectedly dropping a grade in summer examinations".

drowsiness and other side effects of antihistamines
side-effects of other medications (see the specific medication)
asthma
sinusitis
nasal polyps
disruption of lifestyle (usually not too severe)