In the various seasons (spring, summer, and fall) during the year, pollen grains are dispersed from trees, weeds, and grasses. These pollen grains travel on air currents to fertilize other plants. Inhaling pollen, in some people, can trigger seasonal allergic rhinitis which is also called pollen allergy or . In this condition the mucous membranes in the nasal passages inflame, which causes swelling, sneezing, itching, irritation and a runny nose.

Allergy seasons are :

May - July/August - Grass pollen:

Feb - June - Tree pollen (depending on whether allergic to early or late flowering trees)

August - September - Nettle/weed pollen

can continue all the year round and may also occur from indoor allergens like house dust mites, pets and possibly indoor moulds.

Hay fever is actually an attempt by the body to rid itself of allergens but the immune system overreacts and releases chemicals which cause inflammation, causing:

Itchy, watery, red eyes

Frequent sneezing

Constantly dripping nose

Sufferers, when afflicted with this condition, have to struggle to breathe through their nose. Symptoms are often quite bad in young people and tails off in later years as the body adapts. Studies have shown that hay fever can severely affect the quality of life, disturb sleep patterns, impair daytime concentration and work performance.

Pollen once released from trees, weeds and grasses, ride on air currents with a mission to disperse and fertilize other plants. However, they rarely reach their targets. On the way they get into human noses and throats, triggering allergic reactions.

Pollen is one of the most pervasive things that can cause an allergy and cannot be avoided. Many allergy causing foods, drugs, or animals can be largely avoided but insects and household dust are inescapable. However, short of staying indoors, there is no foolproof method of evading windborne pollen. Nonetheless, ways have been established that help ease the symptoms of hay fever. Moreover, scientists are working to find better approaches to allergy treatment.

Research has helped provide a better understanding of the causes of allergy, improve the methods for diagnosing and treating allergic reactions and thereby eventually preventing them. The common signs and symptoms of are:

Sneezing, the most common, may be accompanied by a runny or clogged nose

Itching eyes, nose, and throat

Allergic shiners (dark circles under the eyes caused by restricted blood flow near the sinuses)

The "allergic salute" (in a child, persistent upward rubbing of the nose that causes a crease mark on the nose)

Watering eyes

Conjunctivitis (is inflammation of the membrane that lines the eyelids, causing red-rimmed eyes)

In a pollen-sensitive person, as soon as the allergy-causing pollen lands on the mucous membranes of the nose, a chain reaction occurs that leads the mast cells in these tissues to release histamine. This potent chemical dilates the small blood vessels in the nose; causing the fluids to escape through the expanded vessel walls, which in turn results in swelling of the nasal passages as well as nasal congestion. On the other hand, histamine also causes itching, irritation, and excess mucus production. Similarly, other chemicals like prostaglandins and leukotrienes also contribute to allergic symptoms.

Some people with pollen allergy also develop asthma, a serious respiratory condition, which can eventually become chronic. Symptoms include coughing, wheezing and shortness of breath due to a narrowing of the bronchial passages and excess mucus production.