Overview

Hay fever, also called allergic rhinitis, causes cold-like signs and symptoms, such as a runny nose, itchy eyes, congestion, sneezing and sinus pressure. But unlike a cold, hay fever isn't caused by a virus. Hay fever is caused by an allergic response to outdoor or indoor allergens, such as pollen, dust mites, or tiny flecks of skin and saliva shed by cats, dogs, and other animals with fur or feathers (pet dander).

Besides making you miserable, hay fever can affect your performance at work or school and generally interfere with your life. But you don't have to put up with annoying symptoms. You can learn to avoid triggers and find the right treatment.

Symptoms

Hay fever signs and symptoms can include:

  • Runny nose and nasal congestion
  • Watery, itchy, red eyes (allergic conjunctivitis)
  • Sneezing
  • Cough
  • Itchy nose, roof of mouth or throat
  • Swollen, blue-colored skin under the eyes (allergic shiners)
  • Postnasal drip
  • Fatigue

Seasonal factors

Your hay fever signs and symptoms may start or worsen at a particular time of year. Triggers include:

  • Tree pollen, which is common in early spring.
  • Grass pollen, which is common in late spring and summer.
  • Ragweed pollen, which is common in fall.
  • Dust mites, cockroaches and dander from pets can be bothersome year-round (perennial). Symptoms caused by dander might worsen in winter, when houses are closed up.
  • Spores from indoor and outdoor fungi and molds are considered both seasonal and perennial.

Hay fever or common cold?

Signs and symptoms can be similar, so it can be difficult to tell which one you have.

Condition Signs and symptoms Onset Duration
Hay fever Runny nose with thin, watery discharge; no fever Immediately after exposure to allergens As long as you're exposed to allergens
Onset Runny nose with watery or thick yellow discharge; body aches; low-grade fever One to three days after exposure to a cold virus Three to seven days

When to see a doctor

See your doctor if:

  • You can't find relief from your hay fever symptoms
  • Allergy medications don't provide relief or cause annoying side effects
  • You have another condition that can worsen hay fever symptoms, such as nasal polyps, asthma or frequent sinus infections

Many people — especially children — get used to hay fever symptoms, so they might not seek treatment until the symptoms become severe. But getting the right treatment might offer relief.

Causes

When you have hay fever, your immune system identifies a harmless airborne substance as harmful. Your immune system then produces antibodies to this harmless substance. The next time you come in contact with the substance, these antibodies signal your immune system to release chemicals such as histamine into your bloodstream, which cause a reaction that leads to the signs and symptoms of hay fever.

Risk factors

The following can increase your risk of developing hay fever:

  • Having other allergies or asthma
  • Having atopic dermatitis (eczema)
  • Having a blood relative (such as a parent or sibling) with allergies or asthma
  • Living or working in an environment that constantly exposes you to allergens — such as animal dander or dust mites
  • Having a mother who smoked during your first year of life

Complications

Problems that may be associated with hay fever include:

  • Reduced quality of life. Hay fever can interfere with your enjoyment of activities and cause you to be less productive. For many people, hay fever symptoms lead to absences from work or school.
  • Poor sleep. Hay fever symptoms can keep you awake or make it hard to stay asleep, which can lead to fatigue and a general feeling of being unwell (malaise).
  • Worsening asthma. Hay fever can worsen signs and symptoms of asthma, such as coughing and wheezing.
  • Sinusitis. Prolonged sinus congestion due to hay fever may increase your susceptibility to sinusitis — an infection or inflammation of the membrane that lines the sinuses.
  • Ear infection. In children, hay fever often is a factor in middle ear infection (otitis media).

Prevention

There's no way to avoid getting hay fever. If you have hay fever, the best thing to do is to lessen your exposure to the allergens that cause your symptoms. Take allergy medications before you're exposed to allergens, as directed by your doctor.