The body's defence system that protects us against infections and foreign substances.

An inflammation of the nasal passageways, particularly with discharge.

A chronic disease characterised by an overreaction of the immune system to certain proteins found inside, such as mould spores, pet dander or dust mite allergen, etc. (also called "perennial allergies")

A naturally occurring substance that is released by the immune system after being exposed to an allergen. When you inhale an allergen, mast cells located in the nose and sinus membranes release histamine. Histamine then attaches to receptors on nearby blood vessels, causing them to enlarge (dilate). Histamine also binds to other receptors located i [..]

High-efficiency particulate air (HEPA) filter that removes particles in the air by forcing it through screens containing microscopic pores.

A common trigger for indoor allergies. They are microscopic mites that live in the fibres of pillows, duvets, mattresses, blankets and carpet. They live off of our dead skin cells. Inhalation of their droppings can cause allergic reactions such as nasal congestion.

Allergic reaction caused by the pollens of grasses, trees and other plants whose pollen is spread by the wind.

Inflammation of the skin, either due to direct contact with an irritating substance or to an allergic reaction. Symptoms include redness, itching, and, sometimes, blistering.

A measure of the amount of allergens in the air. The counts are usually reported for mould spores and two types of pollen: grasses and trees. The count is reported as grains per cubic metre of air and is translated into a corresponding level: low, medium, high or very high.

See pollen and mould count.