How to Know If It's a Cold, the Flu, or Allergies

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Is it the flu, a cold, or allergies? If you've ever asked yourself this question, you're certainly not alone. Considering all three unpleasant conditions share similar symptoms, it can be easy to mistake one for another — especially during times throughout the year when all three are prevalent. But it's times like these when knowing how to spot the specific problem messing with your respiratory system is crucial.

“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 Teresa Marie Hauguel, PhD, of the National Institutes of Health.

This is extremely important when it comes to the flu, which has the potential to lead to serious health consequences, such as pneumonia, infections, and even death. But no matter which condition you have, you can only get the right treatment for it if you know what you're treating. Scroll below to learn the main differences between the flu, a cold, and airborne allergies — and don't miss our handy infographic to help you easily tell them apart.

Do I have a cold or the flu?

Admit it: We've all mistaken a cold for a flu, or vice versa. It can be hard to tell them apart at first: Both bring similar unwelcome gifts like a runny, stuffy nose, congestion, coughing, and a sore throat. But a flu can also bring a high fever — which can last up to four days — along with a headache, fatigue, and general aches and pains all over the body. These symptoms are far less common for a cold, according to the National Institutes of Health. While symptoms of a cold tend to develop gradually, the onset of flu symptoms is pretty speedy. There's also a big difference between the two in terms of severity: Symptoms of the flu are generally much more severe than those of the cold. Frighteningly, the complications can be much more severe too; while colds generally do not lead to dire problems in the body, the flu can lead to serious issues like bronchitis, pneumonia, and bacterial infections — and it can also be life-threatening.

Do I have a cold or allergies?

It's pretty easy to mix up a cold with airborne allergies, too. (Been there, done that!) Both can bring on a runny, stuffy nose, as well as sinus drainage and sneezing._ They can also both lead to similar complications, like a sinus infection, a middle ear infection, and asthma. However, it's important to remember that unlike the cold and flu, allergies are not caused by a virus. Instead, allergies are caused by your body's reaction to a certain trigger (such as pollen). Additionally, allergies tend to cause your eyes to itch and water, which usually isn't the case with a cold or flu. Here's the bad news about allergies: While a cold or flu usually goes away after two weeks, allergies can stick around for as long as the allergen sticks around — which could be up to six weeks during, say, pollen season.

Do I have the flu or allergies?

Ask anyone which season they hate most, and we're willing to bet it's either "flu season" or "allergy season." It's the worst when they overlap, isn't it? Pritish Tosh, MD, of Mayo Clinic, says there is one crucial way to rule out an allergic reaction. "Allergies should not come along with a fever," says Dr. Tosh. "If you have a runny nose, cough, and sneezing, along with a fever, it's probably a viral upper respiratory infection." On the other hand, Tosh says if you're experiencing symptoms like itchy eyes, sneezing, and other reactions when you move from one spot to another — like walking outside or stepping inside a certain building — it's most likely an allergy.

Talk to your doctor about what treatments are best for you to treat your condition — especially if your symptoms begin to change or get worse. Let's all do our part to keep ourselves and our loved ones safe and healthy!

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