Understanding Nasal Allergies

Understanding Nasal Allergies

Nasal allergies (also called allergic rhinitis) are a common health problem. They may be seasonal. This means they cause symptoms only at certain times of the year. Or they may be perennial. This means they cause symptoms all year long. Other health problems, such as asthma, often occur along with allergies as well.

Cross section side view of head showing allergens entering nose, swollen nasal lining, and fluid dripping from nasal lining.

What is an allergic reaction?

An allergy is a reaction to a substance called an allergen. Common allergens include:

  • Wind-borne pollen

  • Mold

  • Dust mites

  • Furry and feathered animals

  • Cockroaches

Normally, allergens are harmless. But when a person has allergies, the body thinks they are harmful. The body then attacks allergens with antibodies. Antibodies are attached to special cells called mast cells. Allergens stick to the antibodies. This makes the mast cells release histamine and other chemicals. This is an allergic reaction. The chemicals irritate nearby nasal tissue. This causes nasal allergy symptoms.

Common nasal allergy symptoms

Allergies can cause nasal tissue to swell. This makes the air passages smaller. The nose may feel stuffed up. The nose may also make extra mucus, which can plug the nasal passages or drip out of the nose. Mucus can drip down the back of the throat (postnasal drip) as well. Sinus tissue can swell. This may cause pain and headache. Common allergy symptoms include:

  • Runny nose with clear, watery discharge

  • Stuffy nose (nasal congestion)

  • Drainage down your throat (postnasal drip)

  • Sneezing

  • Red, watery eyes

  • Itchy nose, eyes, ears, and throat

  • Plugged-up ears (ear congestion)

  • Sore throat

  • Coughing

  • Sinus pain and swelling

  • Headache

It may not be allergies

Other health problems can cause symptoms like those of nasal allergies. These include:

  • Nonallergic rhinitis and viruses such as colds

  • Irritants and pollutants, such as strong odors or smoke

  • Certain medicines

  • Changes in the weather


Your healthcare provider will evaluate you to find the cause of your symptoms then recommend treatment. If your symptoms are due to nasal allergies, your healthcare provider may prescribe nasal steroid sprays or oral antihistamines to help reduce symptoms. Avoidance of the allergen will also be suggested. You may also be referred to an allergist. 

Causes of Nasal Allergies

Causes of Nasal Allergies

Nasal allergies are most commonly caused by one or more of 4 kinds of allergens: pollen (which causes seasonal allergies), house-dust mites, mold, and animals. Other substances, called irritants, can bother the nose and make allergy symptoms worse.

Woman holding tissue to nose.


Plants reproduce by moving tiny grains of pollen from plant to plant. Some pollen is carried by bees, and some is blown by the wind. It’s the wind-blown pollen that causes nasal allergies. The amount of pollen in the air varies from season to season.

House-dust mites

House-dust mites are tiny bugs too small to see. They can live in mattresses, blankets, stuffed toys, carpets, and curtains. The droppings of these mites are a common indoor cause of nasal allergies.


Mold loves dark, damp areas. It tends to grow in bathrooms, basements, refrigerators, and in the soil of houseplants. Mold reproduces by sending tiny grains called spores into the air. If these spores are breathed in, they can cause a nasal allergic reaction.


Pets, such as cats, dogs, birds, horses, and rabbits, are common causes of nasal allergies. Flakes of skin (dander), saliva left on fur when an animal cleans itself, urine in litter boxes and cages, and feathers can all cause nasal allergies.

Irritants make allergies worse

Although irritants don’t cause nasal allergies, they can make allergy symptoms worse. Cigarette smoke, perfume, aerosol sprays, smoke from wood stoves or fireplaces, car exhaust, and strong odors are examples of irritants.

Related Problems

Nasal Allergies: Related Problems

Allergies can cause nasal passages to swell. This narrows the air passages. Allergies also cause increased mucus production in the nose. These changes result in nasal allergy symptoms. Common symptoms include itching, sneezing, stuffy nose, and runny nose. Nasal allergies can also cause problems in other parts of the respiratory system. Some of the more common problems are discussed below. If you think you have any of these problems, talk to your healthcare provider about treatment choices.

Outline of man's head and chest with head turned to side. Inside of nose and mouth are visible. Trachea leads from throat and branches into lungs. Sinuses are spaces in head, some filled with fluid with swollen lining from nasal allergies. Polyps are deep inside nose. Fluid dripping from nose lining down back of throat. Eye is red and swollen.

Sinus infections

Fluid may be trapped in the sinuses. Bacteria may grow in trapped fluid. This causes sinus infection (sinusitis).


Allergens irritate your eyes, including the lining of the conjunctiva. This causes eyes to become red, itchy, puffy, and watery.

Ear problems

The eustachian tube connects the middle ear to nasal passages.  Allergies can block this tube, and make the ears feel plugged. Fluid may also build up, leading to an ear infection (otitis media).

Nasal polyps

Allergies cause nasal passages to swell. Constant swelling can lead to formation of a sac called a polyp. Polyps can grow large enough to block nasal passages.


Asthma is inflammation and swelling of the air passages in the lungs. The symptoms are wheezing, shortness of breath, coughing, and chest tightness. Allergies, including nasal allergies, are common in people with asthma.