People want to know what causes hay fever. At one point or another, people will suffer form allergies. These allergies are most commonly expressed as hay fever. Its symptoms include itchy and puffy eyes, as well as a stuffed up nose. Doctors refer to it as allergic rhinitis. It is essentially an allergic reaction to foreign material.
One out of every five people suffers from a form of hay fever. It has no gender preferences. It is often seasonal, though some can experience it throughout the year.
Hay fever is caused by an allergic reaction. The allergens are traditionally airborne and enter the body through the airways, such as the throat, nose and lungs. They enter the body when a person breathes. In some cases, the allergic enters through the eye lining or direct contact to the ears. It is often extremely difficult to identify the specific allergen that caused the attack.
Symptoms begin once the allergens enter the airway. The body then produces an inordinate amount of antibodies, which leads to a hypersensitivity reaction, or an allergic reaction. When the antibody comes into contact with the specific antigen, it releases chemicals known as mediators. Histamines are a common example of mediators. These mediators are what actually cause allergic reactions or hay fever.
Most of the time, hay fever is caused by pollen, which comes from flowering plants. These plants spread pollen around to fertilize other plants. This allows them to bloom again. Some plants species can cause allergic reactions more easily than others. Pollination varies from plant to plant. Some plants pollinate in the fall, others during the summer. A good rule of thumb is that the further north a plant lives, the later in the season it will decide to pollinate. Temperature variations can also affect the amount of pollen in the area.
Mould can also cause hay fever. Mould is a kind of fungus. It has no leaves, roots or stems. Mould spores float much in the same way that pollen does. They do so until the find a pleasant place to grow. There is no season to them. They are present throughout the year.