How to Tell the Difference Between Flu and Allergies
Seasonal allergy, or "hay fever," can make you feel lousy. Or is it the flu?

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How to Tell the Difference Between Flu and Allergies

If you have allergies, you know that certain seasons can send you rushing for the tissue box. So-called "hay fever" tends to flare up in the spring and fall. The peak time for the seasonal flu can overlap these seasons, too.

Some of the symptoms, like a runny nose and cough, are common to both allergies and the flu. It's important to know the difference, so you can seek the proper treatment and medications.

Hay fever
"Hay fever" is really not a fever. It is known to doctors as seasonal allergic rhinitis. Fever is not one of the symptoms.

An allergic reaction happens when the body mistakes a harmless substance like pollen as an intruder. The immune system kicks into gear, creating chemical helpers to respond. These cause the symptoms of allergies.

As long as pollen is in the air, people who are allergic to it will often be sneezing or have a runny and stuffed-up nose. They may also feel itchy in their eyes, nose, throat and mouth.

In North America, the biggest pollen culprits are weeds. Ragweed is No. 1 on the list. Others are sagebrush, redroot pigweed, lamb's quarters, English plantain and tumbleweed. Trees and grasses can also release pollen.

Flu (influenza)
The flu is caused by a virus that is mainly spread by droplets created when people cough, sneeze or talk. The flu usually comes on suddenly. It can be mild or very serious - even resulting in death. People with the flu may have fever, cough, sore throat, body aches, runny or stuffed-up nose, headaches and extreme tiredness.

Complications include ear and sinus infections, bronchitis and pneumonia. If it does not lead to complications, the flu typically lasts between a few days and two weeks. Remember, the single best way to prevent the flu is good hand washing and getting a vaccination every year. If you believe you have the flu, call your doctor right away. He or she may prescribe antiviral medications.

If you suspect you have the flu, go to the CDC's website for more information.

See how symptoms of allergies and the flu compare:







Itchy eyes and nose



Runny or stuffy nose

Common, clear discharge

Common, yellow discharge



Common, can become severe

Body aches





Usually, often severe

By Emily Gurnon, Contributing Writer
Created on 05/06/2009
Updated on 02/10/2013
  • Asthma and Allergy Foundation of America. Flu/cold or allergies?
  • Centers for Disease Control and Prevention. Flu symptoms and severity.
  • National Institute of Allergy and Infectious Diseases. Pollen allergy.
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