What Causes a Sore Throat?
Most sore throats are caused by viral infections like the common cold or flu and resolve on their own within a week. A smaller number are caused by bacteria, most notably strep throat, which needs antibiotics.
Common Causes
- Viral infections (cold, flu, mononucleosis)
- Strep throat (bacterial)
- Allergies and postnasal drip
- Acid reflux (GERD)
- Dry air or irritants (smoke, pollution)
- Tonsillitis
Strep Throat vs. Viral — Key Differences
| Feature | Strep Throat | Viral Sore Throat |
|---|---|---|
| Onset | Sudden | Gradual |
| Fever | Often high | Usually mild |
| Cough | Usually absent | Common |
| Swollen tonsils with white patches | Common | Less common |
| Swollen neck lymph nodes | Common | Variable |
Tests Your Doctor May Order
| Test | Purpose |
|---|---|
| Rapid strep test | Detects strep bacteria within minutes |
| Throat culture | Confirms strep if rapid test is negative but suspicion is high |
| CBC | Checks for infection, especially if mononucleosis is suspected |
See a doctor if: Severe difficulty swallowing or breathing, drooling, a sore throat lasting more than a week, or a high fever above 39.4°C (103°F).
Important: Sore throat with high fever, difficulty breathing or swallowing needs prompt medical evaluation.