Authored by Revere Health

Allergies or a Cold? How to Tell the Difference

September 1, 2017 | Allergy and ImmunologyEar, Nose, Throat

Many medical conditions share similar symptoms, and a good example is allergies and the common cold. The two conditions share symptoms like a runny nose and excess mucus, and it can often be difficult to tell the difference between the two.

Fortunately, there are some tell-tale signs of each condition if you know where to look. Here are some basic facts about allergies and the common cold, how to tell them apart and when a doctor’s care becomes necessary.   

Basic Facts

When broken down by their underlying causes, it’s easy to see how allergies and the cold are different. The cold is actually a form of infection, caused by a virus in the body. Allergies, on the other hand, represent the immune system’s response to certain triggers like pollen or pet dander. Colds can be passed through the air and through touch, while allergies cannot.

Allergies Are Likely If:

If you notice the following circumstances when you have these kinds of symptoms, it’s likely your condition is allergies and not a cold:

  • Clear, watery mucus: Mucus will begin clear and stay that way throughout your symptoms. This is in contrast to a cold, where mucus often becomes thick and discolored as the cold progresses.
  • Itchy or watery eyes: Itchy eyes are relatively rare during a common cold, but they’re a common symptom of allergies.
  • Symptoms remain constant: While cold symptoms may increase or decrease as the illness wears on, symptoms of allergies will generally remain consistent each day—with the exception of the first day or two in some cases.
  • Timing: A cold generally clears up within 7 to 10 days. Allergy symptoms, however, can last for weeks or longer.
  • Situational triggers: In many cases, allergies only occur in certain situations or at certain times of the year. Many people have seasonal allergies in the spring or fall, for instance. The cold, on the other hand, can show up at any point but is most common in late fall and winter.

Cold Is Likely If:

On the other hand, it’s more likely you have a cold if the following circumstances are present:

  • Cough, fever, headache or mild body aches: Different cold viruses cause different symptoms, but these are some of the most common—and more importantly, some of the symptoms you almost never see with allergies. One exception here is people who have asthma, who may see allergies trigger a cough from post-nasal drip.
  • Symptoms change: As we noted above, allergy symptoms generally remain constant after the first day or two. Cold symptoms, though, may change frequently, starting with a fever and stuffy nose, then sore throat, then possibly a cough or sinus pain.
  • Mucus thickens and changes color: Allergy mucus is clear and thin, but mucus from the common cold can become thick or discolored as time goes on.

When to Call a Doctor

Call your doctor if…

  • You suspect you have allergies: Your doctor can recommend treatments or refer you to an allergist for testing.
  • You’re having trouble breathing, have a skin rash or have swelling in your mouth (could be signs of severe allergic reaction).
  • You have a fever over 101 degrees Fahrenheit.
  • Your cold symptoms get worse and don’t clear up after 10 days (could signal an issue like pneumonia).

If your symptoms are disrupting your quality of life, consult with a doctor to find the best treatment and prevention method for you.


“Allergies, Cold or Flu: Why Do You Feel Icky?” WebMD.

“Is It Allergies or a Cold?” Healthline.


The Live Better Team

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This information is not intended to replace the advice of a medical professional. You should always consult your doctor before making decisions about your health.