Colds and allergies share a runny or stuffy nose and sneezing, so they’re easy to mix up. Three clues usually tell them apart: fever, itchy eyes and how long symptoms last. According to Mayo Clinic, people with seasonal allergies never get a fever from them and usually have itchy eyes, while a cold can bring a fever and sore throat but rarely itchy eyes. A cold usually clears within about 10 days; allergies can last for weeks.
This guide compares symptoms side by side, explains timing clues, and covers treatment and when to see a doctor. For more, see our seasonal allergy guides.
Jump to: Quick answer · Symptom comparison · Timing clues · What causes each · Treatment · When to see a doctor · FAQ
Quick answer
- Fever points to a cold. Mayo Clinic says allergies never cause fever; colds sometimes do.
- Itchy eyes point to allergies. They’re usual with allergies and rare with colds.
- Sore throat points to a cold. It’s usual with colds and rare with allergies.
- Duration: a cold lasts about 3 to 10 days in adults (a cough can linger); seasonal allergies may last several weeks.
- Pattern: “colds” that come back every spring or fall may really be allergies.
Symptom comparison
| Symptom | Cold | Allergy |
|---|---|---|
| Fever | Sometimes | Never |
| Itchy eyes | Rarely | Usually |
| Sore throat | Usually | Rarely |
| Sneezing | Usually | Usually |
| Tiredness | Sometimes | Sometimes |
| Runny nose | Usually | Usually |
| Stuffy nose | Usually | Usually |
| Cough | Usually | Sometimes |
Source: Mayo Clinic, “Cold or allergy: Which is it?” Mayo Clinic also notes that seasonal allergies can cause puffy eyelids and dark marks under the eyes.
Timing clues
- How fast it builds: the CDC says cold symptoms usually peak within 2 to 3 days of infection.
- How long it lasts: colds usually last less than a week to about 10 days; allergy symptoms continue as long as you’re exposed to the trigger.
- When it happens: if “colds” arrive at the same time every year, such as spring tree pollen or late-summer ragweed season, allergies are likely. See do seasons affect allergies?
- Where it happens: symptoms that flare around pets, dust or certain places suggest allergies.
What causes each
Colds are caused by viruses. The CDC says more than 200 respiratory viruses can cause colds, and rhinoviruses are the most frequent cause in the U.S. Common cold symptoms include a runny nose, congestion, cough, sneezing, sore throat, headache, mild aches and sometimes a mild fever.
Allergies happen when the immune system reacts to harmless substances like pollen, dust mites, mold or pet dander. Weather changes and irritants can also cause allergy-like symptoms without an allergy (nonallergic rhinitis).
Treatment
| Cold | Allergies |
|---|---|
| Rest and fluids | Avoid triggers where possible |
| Pain relievers for aches or sore throat | Nasal steroid sprays, the most effective drug class for hay fever (ACAAI) |
| Nasal rinses or sprays for congestion | Antihistamines; saline rinses |
| Antibiotics don’t help viral colds | Allergy shots or tablets for long-term relief |
Treatment suggestions from Mayo Clinic unless noted. For more, see how to use a neti pot safely, salt water gargles, allergy drops vs shots and do sinus infections need antibiotics?
When to see a doctor
- Symptoms last more than 10 days without improving, or get worse after improving.
- You have a high or long-lasting fever.
- You have wheezing, shortness of breath or chest tightness.
- “Colds” keep coming back at the same time each year, which may mean allergies worth testing for.
Flu and COVID-19 can also look like a cold; testing can tell them apart.
This guide is general information, not medical advice. Read our medical disclaimer.
Frequently asked questions
How can I tell if I have a cold or allergies?
Fever and sore throat suggest a cold; itchy eyes suggest allergies. Colds usually clear within about 10 days, while allergies last as long as you’re exposed to the trigger.
Can allergies cause a fever?
No. Mayo Clinic’s comparison lists fever as “never” for allergies. A fever points to an infection.
How long does a cold last?
About 3 to 10 days in adults, according to Mayo Clinic, though a cough can last a couple of weeks longer.
Why do I get a “cold” every spring?
It may be seasonal allergies, especially if you have itchy eyes and no fever. An allergist can test for pollen allergy.
Do antibiotics help a cold?
No. Colds are caused by viruses, and antibiotics don’t work on viruses.
Sources
- Mayo Clinic Staff. Cold or allergy: Which is it? February 13, 2024.
- Centers for Disease Control and Prevention. About common cold. February 19, 2026.
- American College of Allergy, Asthma and Immunology. Hay fever (rhinitis).
Last reviewed: October 21, 2026.
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