Understanding Hay Fever -- the Basics

Medically Reviewed by Nayana Ambardekar, MD on June 06, 2023
6 min read

Hay fever is an allergic reaction to certain things. Common triggers include pollen, ragweed, and cats.

Also known as allergic rhinitis, there are two types: seasonal, which happens only during the time of year in which certain plants pollinate, and perennial, which happens year-round.

Typically, if you suffer from hay fever in the spring, you're probably allergic to tree pollens. Grass and weed pollens may be causing your allergic reaction during the summer. In autumn, ragweed pollen may plague you, and fungus spores cause problems primarily from late March through November but can be present year-round.

People with year-round (perennial) hay fever are usually allergic to one or more allergens found indoors. These include house dust mites, feathers, and animal dander (the tiny skin flakes animals such as cats and dogs shed along with fur), all of which may be found in pillows, bedding, heavy draperies, upholstery, and carpeting. Another common allergen, mold, is usually found in damp areas such as bathrooms and basements.

If you have hay fever (allergic rhinitis), it's because your immune system views harmless inhaled pollen or other allergens as dangerous substances invading the body. Your system overreacts, flooding your bloodstream with chemicals like histamine and leukotrienes. These inflame the lining of your nasal passages, sinuses, and eyelids and also set in motion other symptoms associated with hay fever, such as:

All of these symptoms are meant to protect your body either by trapping and expelling the allergen or by swelling body areas, such as the nasal passages, so the allergen can't enter. As a result of congestion in the veins in the lining of your sinuses, dark circles, commonly known as allergic shiners, may appear under your eyes. If you have perennial allergic rhinitis, they may be present all year round. The swelling of your nasal membranes may also close the sinus drainage openings, causing sinusitis. Rhinitis may also be associated with nasal polyps -- small, non-cancerous growths. And nosebleeds can occur during hay fever attacks.

Hay fever is often an inherited trait (genetically determined). Most people with hay fever have a parent or sibling who also has allergies. People with asthma or eczema (allergic dermatitis) are more likely than others to develop hay fever; and about one-third of those with allergic rhinitis also have at least mild, intermittent, allergic asthma.

See a doctor if:

  • Your allergy symptoms are affecting your quality of life.
  • Your hay fever does not go away.
  • Over-the-counter (OTC) medicines don't help or have unpleasant side effects.
  • You have other problems, like asthma, chronic sinus infections, or polyps in your nose.

Many people try to live without treating hay fever, but treatment can help ease your symptoms. Getting help for your symptoms early can put you on the right track for improving your allergies.

Before you see the doctor, think about when and where your symptoms show up.  For example:

  • Tree pollens typically appear in early spring.
  • Grasses shed pollen in late spring and summer.
  • Ragweed makes pollen in the fall.
  • Indoor allergies might get worse in winter.
  • Indoor and outdoor molds, along with pet dander, might trigger symptoms year-round.

If your symptoms go away after about a week, you could have a cold and not an allergy.

It may take several tries to ease your symptoms. First, you should stay away from triggers as much as you can. Second, you should take the medicines your doctor suggests or prescribes as directed. That will help them work better.

Corticosteroid nasal sprays. You can use them long-term to treat symptoms like itching, runny nose, and congestion. They usually provide relief within 12 hours of your first dose. They include budesonide, fluticasone, and mometasone.

Antihistamines. These are pills, nose sprays, and eye drops that work best on hay fever symptoms like runny nose, sneezing, and itchy eyes and skin. Options include cetirizine, fexofenadine, and loratadine. These are often preferable to older products (your doctor may call them first-generation antihistamines), which typically cause drowsiness.

Decongestants. They help relieve the swelling inside your nose that makes it stuffy. Don't use nose drops and sprays longer than 5 days. Your nose gets used to them and congestion returns. Your doctor may call this rebound swelling.

Cromolyn sodium. Use this OTC nasal spray several times a day to stop the release of histamines. It works best when you start before symptoms show up.

Leukotriene modifier. This medicine hinders leukotrienes, chemicals in your immune system that cause your body to make extra mucus.  A leukotriene modifier like montelukast can help when allergy symptoms come with mild asthma.

Nasal ipratropium. This prescription nose spray helps stop an extra-runny nose but doesn't do much for symptoms like congestion or sneezing. Don't take it if you've been diagnosed with glaucoma or an enlarged prostate gland.

This treatment aims to make your body less reactive. It doesn't work for every allergen. It seems to help most with common environmental triggers.

The first step is to find out what you're allergic to. Your doctor will do this with a skin prick test or by injecting small doses of the allergen under your skin.

When you react, you're allergic to that substance. After that, you'll get shots with small doses of the things you're allergic to -- usually one at a time. Your doctor will slowly increase the dose until you get to the largest amount you can tolerate. You must visit your doctor regularly, often weekly, for as many as 2 to 5 years.

In 2014, the FDA approved sublingual immunotherapy for treatment of grass and ragweed pollens. It works by placing a tablet or liquid under the tongue daily. It's best to begin this therapy several months before allergy season begins.

You can ease your allergy symptoms by avoiding or reducing your exposure to triggers. For seasonal allergies, you should:

  • Stay indoors as much as possible during peak pollen counts and windy days. Ragweed is highest in the morning. Tree and grass pollens peak in the early evening.
  • Close windows and use your air conditioner.
  • Wear glasses or sunglasses to keep pollen out of your eyes.
  • Wear a mask when you work outdoors.

For perennial allergies to indoor animals and pests:

  • Use dust mite-proof covers for pillows and mattresses.
  • Wash your sheets and blankets often in hot water.
  • Keep humidity levels down in your home with dehumidifiers and air conditioning.
  • Wash your hands after you touch animals.
  • Keep your pet out of your bedroom while you sleep.
  • Replace carpets with hardwood, tile, or linoleum flooring.
  • Use a HEPA filter on your HVAC system and your vacuum.

Saline rinses. They can ease nasal congestion and wash allergens and extra mucus out of your nose. You can use a premixed solution in a squeeze bottle or a neti pot. Use distilled, sterile, or boiled water if you decide to make the saline mixture yourself. Use purified water to rinse and sterilize the bottle or neti pot after each use. Let them air dry.

Bioelectronic sinus device. This works by using microcurrents to stimulate nerve fibers in your sinuses. Sold over-the-counter, it helps reduce sinus inflammation, pain, and congestion. 

Herbal remedies.  There's some evidence that a shrub called butterbur may help hay fever symptoms. The raw plant can be toxic. Choose a product labeled “PA-free.” Other herbal remedies include capsicum, honey, vitamin C, and fish oil, but more research is needed to know how well they work.  Some people use acupuncture to treat hay fever.

Although there's no cure for hay fever, if you work with your doctor, stick to your treatment plan, and avoid the triggers for your seasonal and perennial allergies, you can manage your symptoms before they manage you.