A painful tonsil is almost always caused by an infection, but the specific type of infection, and whether it needs treatment, varies. Viruses account for up to 70% of tonsillitis cases, while bacteria (most notably strep) cause most of the rest. Less commonly, tonsil pain comes from something non-infectious: a tonsil stone, postnasal drip, or a buildup of pus called an abscess. Understanding which category your pain falls into helps you figure out what to do next.
Viral Tonsillitis: The Most Common Cause
The same viruses behind the common cold and flu are responsible for the majority of tonsil infections. Viral tonsillitis tends to produce milder symptoms compared to bacterial infections. You’ll likely notice a sore throat, mild swelling, and general fatigue, often alongside a runny nose, cough, or sneezing. The pain usually resolves on its own within about a week without any specific treatment beyond rest, fluids, and over-the-counter pain relievers.
Mononucleosis (mono) is a viral infection worth knowing about separately because it behaves differently. Mono can cause noticeably swollen tonsils along with fever and a severe sore throat. The fever and throat pain typically ease within a couple of weeks, but fatigue, swollen lymph nodes, and an enlarged spleen can linger for several weeks beyond that. Mono is especially common in teenagers and young adults.
Bacterial Tonsillitis and Strep Throat
Bacterial tonsillitis, most often caused by group A streptococcus (strep), generally hits harder than viral infections. The pain tends to be more intense, and you may see white or yellow patches of pus on the tonsils. A high fever (above 100.4°F), swollen and tender lymph nodes in the front of your neck, and the absence of a cough are classic signs pointing toward strep rather than a virus. Doctors use these specific features, along with your age, to estimate the likelihood of a strep infection before deciding whether to run a rapid strep test.
Bacterial tonsillitis takes about 10 days to run its course and typically requires antibiotics. The antibiotics aren’t just about comfort. They reduce the risk of complications like rheumatic fever and peritonsillar abscess, and they shorten the window during which you can spread the infection to others. If you’re prescribed a full course, finishing it matters even after you start feeling better.
When Only One Tonsil Hurts
Pain on just one side is a pattern worth paying attention to. While ordinary tonsillitis can sometimes feel worse on one side, one-sided pain that gets progressively more severe raises the possibility of a peritonsillar abscess. This is a pocket of pus that forms in the tissue next to a tonsil, usually as a complication of an untreated or undertreated bacterial infection.
A peritonsillar abscess produces a distinctive set of symptoms beyond just throat pain. You may have trouble opening your mouth fully, your voice may sound muffled or “hot potato”-like, and you might notice drooling because swallowing becomes too painful. In some cases, the swelling pushes the uvula (the small tissue hanging at the back of your throat) visibly to one side. Swelling of the face or neck can also develop. This is a condition that needs prompt medical attention because the swelling can grow large enough to partially block your airway. If breathing becomes difficult, that’s an emergency.
Tonsil Stones
Tonsil stones are small, hardened lumps that form when food debris, bacteria, and minerals like calcium get trapped in the folds of your tonsils. These folds, called tonsillar crypts, tend to deepen with repeated tonsil infections, making stones more likely over time. Most tonsil stones are small and cause no symptoms at all, but larger ones can create a persistent sore throat, bad breath, difficulty swallowing, earache, or a nagging sensation that something is stuck in your throat.
Small stones sometimes dislodge on their own through coughing or gargling. Larger or recurring stones that cause ongoing discomfort can be removed by a healthcare provider. The pain from tonsil stones is generally milder and more chronic than the acute pain of an infection, which can help you tell the difference.
Non-Infectious Causes
Not all tonsil pain comes from germs. Postnasal drip, where excess mucus drains down the back of your throat, can irritate and inflame the tonsils and surrounding tissue. Allergies are one of the most frequent causes of postnasal drip, but cold or dry air, weather changes, and chronic acid reflux (GERD) can all trigger it as well. If your tonsil pain comes and goes with seasonal allergies or tends to be worse in the morning after lying flat all night, postnasal drip is a likely contributor.
Acid reflux deserves a specific mention. Stomach acid that travels up into the throat, especially at night, can cause a low-grade but persistent burning or soreness in the tonsil area. This kind of pain often doesn’t come with the fever or swollen lymph nodes you’d expect from an infection.
Easing Tonsil Pain at Home
While you’re waiting for your body to fight off an infection, or while figuring out the underlying cause, a few straightforward measures can reduce discomfort. Gargling with warm salt water is one of the simplest. The recommended ratio is a quarter to half teaspoon of table salt mixed into eight ounces of warm water. The salt creates a solution that draws fluid and debris out of swollen tissue, temporarily reducing inflammation.
Cold liquids, ice pops, and soft foods can soothe an inflamed throat. Over-the-counter pain relievers like ibuprofen or acetaminophen help with both pain and fever. Staying hydrated is important because swallowing less due to pain can lead to mild dehydration, which makes the soreness feel worse. Using a humidifier in dry indoor air can also reduce irritation, especially overnight.
Signs That Need Medical Attention
Most tonsil pain from a viral infection will resolve within a week. Certain patterns, though, signal something that needs professional evaluation. Severe pain concentrated on one side, difficulty opening your mouth, a muffled voice, or visible swelling in the neck or face all suggest a possible abscess. A fever above 100.4°F combined with swollen lymph nodes and pus on the tonsils points toward strep, which benefits from antibiotic treatment. Pain that persists beyond 10 days, keeps coming back, or is accompanied by unexplained weight loss or a lump in the neck warrants a closer look. And any difficulty breathing should be treated as an emergency.