Scientists think that people inherit a tendency to have allergies from their parents. Exposure to allergens when your body’s defense is weakened, like after being sick, may also contribute to the development of allergies.

When you inhale, itty-bitty allergens enter your body through your nose, mouth and lungs and can trigger an allergic reaction.

Even though you may be born with a tendency for allergies, you’re not automatically going to have an allergic reaction. It may take several years to become sensitive to a specific allergen, such as pet dander.

You may become sensitive to an allergen when:

• You inherit specific genes from your parents

• You come in contact with one or more allergens that your genes tell your body to stay away from

• You are around pesky allergens often

Learn essential allergy terminology so you can better understand how allergies affect you and your family.

Allergic rhinitis - swelling or inflammation in the nose and nasal membranes, due to an allergic reaction

Allergic conjunctivitis - itching, redness, swelling or tearing of the eyes, due to an allergic reaction

Antihistamine - a drug that reduces the effects of histamine, a substance released by your body during an allergic reaction

Animal Dander - old animal skin scales, including oils proteins, which are constantly shed by animals, more so by older ones.

Dust - a combination of dirt, mold, pollens, hair, food particles, dust mites, human skin and any other small particles floating in the environment.

Dust mites - microscopic relatives of the spider that live on beds, pillows, upholstery, carpets and curtains. These tiny creatures feed on the flakes of skin shed by both humans and animals.

HEPA filter - high-efficiency particulate air filter - removes particles in the air by forcing it through screens containing microscopic pores.

Histamine - a chemical released in the human body during an allergic reaction, causing congestion, itching, sneezing and other uncomfortable symptoms.

Mold - fungus that thrive in dark, warm, humid locations indoors and outdoors.

Perennial allergies - allergic reactions that occur throughout the year, as opposed to a few specific times

Pollen - the tiny, egg-shaped male cells released from flowering plants including trees, grasses and weeds, for reproduction.

Pollen count - the number of pollen grains per cubic meter in the air at any given time

Ragweed - a yellow flowering weed, also the number one cause of fall allergy symptoms.

Seasonal allergies - allergic reactions that occur at specific times of the year as a result of exposure to seasonal allergens in the environment.

Spores - another common cause of allergic reactions, spores are the smallest particles release from mosses and fungi for reproduction.