Allergies Cold, Flu, or Allergy Do You Know the Difference?

Flu and YouYou’re feeling pretty lousy. You’ve got sniffles, sneezing, and a sore throat. Which is to blame: a cold, flu, or allergies? It can be hard to tell them apart because they share so many symptoms, but understanding the differences will help you choose the best treatment for what ails you.

“If you know what you have, you won’t take medications that you don’t need, that aren’t effective, or that might even make your symptoms worse,” says National Institutes of Health’s Dr. Teresa Hauguel, an expert on infectious diseases that affect breathing.

Colds, flu, and allergies all affect your respiratory system, which can make it hard to breathe. Each condition has key symptoms that set it apart.

Colds and flu are caused by different viruses. “As a rule of thumb, the symptoms associated with the flu are more severe,” says Dr. Hauguel. Both illnesses can lead to congestion, cough, sore throat, and a runny, stuffy nose. But the flu can also cause high fever that lasts for three to four days, along with a headache, fatigue, and general aches and pain. These symptoms are less common when you have a cold.

“Allergies are a little different, because they aren’t caused by a virus,” Dr. Hauguel explains. “Instead, it’s your body’s immune system reacting to a trigger, or allergen, which is something you’re allergic to.” If you have allergies and breathe in things like pollen or pet dander, your delicate respiratory tissues may swell, and your nose may become stuffed up or runny.

“Allergies can also cause itchy, watery eyes, which you don’t normally have with a cold or flu,” Dr. Hauguel adds.

Allergy symptoms usually last for as long as you’re exposed to the allergen, which may be about six weeks during pollen seasons in the spring, summer, or fall. Colds and flu rarely last beyond two weeks.

To treat colds or flu, get plenty of rest and drink lots of fluids. If you have the flu, pain relievers such as aspirin, acetaminophen, or ibuprofen can reduce fever or aches. See your doctor if symptoms last beyond 10 days or if symptoms aren’t relieved by over-the-counter medicines. Allergies can be treated with antihistamines, decongestants, nasal steroids, or immunotherapy. Your doctor can help you choose the best treatment based on your symptoms.

Be careful to avoid drug overlap when taking medicines that list two or more active ingredients on the label. For example, if you take two different drugs that contain acetaminophen – one for a stuffy nose and the other for headache – you may be getting too much acetaminophen.

“Read medicine labels carefully – the warnings, side effects, dosages. If you have questions, talk to your doctor or pharmacist, especially if you have children who are sick,” Dr. Hauguel says. “You don’t want to overmedicate, and you don’t want to risk taking a medication that may interact with another.”

Chart comparing Cold and Flu

Source: National Institutes of Health,

This article was originally published in Coping® with Allergies & Asthma magazine, WINTER November 2014-February 2015.