Allergies vs Colds
How to tell the difference between allergies (such as hay fever) and colds: causes, timing, typical features, treatment overview and when a clinician should check.
Content last updated . This page has not been medically reviewed.
Two different things with overlapping symptoms
Both colds and seasonal allergies can cause a runny or blocked nose, sneezing and a cough. The causes differ. A cold is an infection by a virus. [1] An allergy is a reaction by your immune system to something that does not bother most other people. [2] This page is educational; it cannot tell you which one you have.Side by side
| Feature | Cold | Allergy (hay fever) |
|---|---|---|
| Cause | One of more than 200 viruses [1] | Immune reaction to pollen and similar triggers [3][2] |
| How long | Usually goes away after 1 to 2 weeks [3] | Can last weeks or months [3] |
| Itchy, red or watery eyes, itchy throat, mouth, nose or ears | Not listed as main cold symptoms [4] | Listed as hay fever symptoms [3] |
| Fever and aching muscles | May occur [4] | Not listed among hay fever symptoms [3] |
| Contagious | Yes, spreads from person to person [1] | No. (An allergy is an immune reaction, not an infection.) [2] |
| Timing | More common in winter and spring, but any time [1] | Often worse from late March to September, when pollen is high (in the UK) [3] |
Tip: a pattern that returns at the same time every year, or follows exposure to pets, dust or pollen, points toward allergy, while a high temperature and aches point toward infection. These are general clues, not a diagnosis. Allergy triggers include pollen, dust mites, mold spores, pet dander, food, insect stings and medicines. [2]
What helps
- Colds: rest, fluids and pain relief as needed; antibiotics do not help. [1] See colds, flu and respiratory infections.
- Hay fever: there is no cure, but you can reduce pollen exposure (showering after being outside, keeping windows shut) and a pharmacist can suggest antihistamines or steroid nasal sprays. [3] Some antihistamines make you very sleepy. [3] If other treatments fail, a GP may refer for immunotherapy, where small amounts of pollen are given to build tolerance. [3]
- Smoke: the NHS advises avoiding smoke for hay fever and notes smoking makes cold symptoms worse. [3][4]
Supplements, "immune boosters" and honey products are not established treatments for hay fever, and this section does not cover them in detail. If you are considering one, check medication interactions and natural does not mean safe. Echinacea belongs to the daisy and ragweed family, and some people have allergic reactions to it. [5] See echinacea.
When to get help
See a GP if hay fever symptoms get worse or do not improve with pharmacy medicines. [3] Allergic reactions can range from minor to severe, and anaphylaxis is severe and life-threatening. [2] If you think someone is having a severe allergic reaction, treat it as an emergency and use your local emergency number (911 in the US). For cold-type illness, see the warning signs on the colds page.Frequently asked questions
How can I tell allergies from a cold?
Hay fever symptoms (sneezing, itchy eyes, runny nose) can last weeks or months, unlike a cold, which usually passes in 1 to 2 weeks. [3]
Are allergies contagious?
No. A cold is spread by viruses; an allergy is an immune reaction to a trigger. [1][2]
Can allergies be cured?
The NHS says there is currently no cure for hay fever, but symptoms can be eased. [3]
Are hay fever and cold treatments the same?
No. Hay fever is treated with antihistamines or steroid nasal sprays, and colds with rest, fluids and pain relief; antibiotics do not help colds. [3][1]
References
- MedlinePlus (U.S. National Library of Medicine). Common Cold. Read 2026-10-22.
- MedlinePlus (U.S. National Library of Medicine). Allergy. Read 2026-10-22.
- NHS. Hay fever. Read 2026-10-22.
- NHS. Common cold. Read 2026-10-22.
- National Center for Complementary and Integrative Health (NIH). Echinacea: Usefulness and Safety. Read 2026-10-22.