Swollen tonsils usually mean your immune system is reacting to an infection or irritation in your throat, but the seriousness ranges from “minor viral bug” to “need urgent care today.”

Why are my tonsils swollen?

Your tonsils are immune tissue that sit at the back of your throat and act like guards , catching germs that come in through your mouth and nose. When they detect trouble, they can become inflamed, red, and enlarged (tonsillitis).

Common causes (most to less likely)

  • Viral infections (very common)
    • Colds and flu (adenovirus, rhinovirus, influenza, etc.).
    • Symptoms: sore throat, runny or stuffy nose, mild fever, cough, body aches, tiredness.
  • Strep throat and other bacterial infections
    • Caused often by group A streptococcus.
    • Symptoms: sudden very sore throat, painful swallowing, fever, swollen tonsils (often with white patches or pus), swollen neck glands, headache; usually no cough.
  • Mononucleosis (“mono”)
    • Caused by Epstein–Barr virus.
    • Symptoms: very swollen tonsils, extreme fatigue, fever, sore throat, swollen glands, sometimes enlarged spleen; common in teens/young adults.
  • Reflux (acid coming up to the throat)
    • Laryngopharyngeal reflux can irritate the throat and tonsils.
    • Symptoms: chronic throat clearing, lump-in-throat feeling, hoarseness, cough, sometimes heartburn or sour taste.
  • Allergies and irritants
    • Pollen, dust, smoke, pollution can inflame the upper airway and contribute to tonsil swelling.
    • Symptoms: itchy or watery eyes, sneezing, post-nasal drip, congestion, mild sore throat rather than severe pain.
  • Dental or mouth infections
    • Gum disease or tooth abscess can spread inflammation to nearby tissues including tonsils.
    • Symptoms: tooth or gum pain, bad breath, localized swelling, plus sore throat.
  • Less common / more serious causes
    • Peritonsillar abscess (pocket of pus around a tonsil), chronic tonsillitis, immune problems, or rarely tumors/lymphoma in adults.
    • These are less common but important to rule out if symptoms are severe, one‑sided, or persistent.

Red‑flag signs: see urgent care or ER

Get urgent in‑person medical help today (ER or urgent care) if you have any of these along with swollen tonsils:

  1. Trouble breathing, noisy breathing, or feeling like your throat is closing.
  2. Difficulty swallowing saliva or drooling because it hurts too much to swallow.
  3. Very muffled or “hot‑potato” voice, or you can’t open your mouth well.
  4. Severe one‑sided throat pain with visibly larger tonsil on one side.
  5. High fever, feeling very unwell, or neck stiffness.
  6. Swelling or pain in the neck, or you can’t move your neck normally.
  7. A weakened immune system (HIV, chemotherapy, long‑term steroids, etc.).

These can signal a peritonsillar abscess or other serious infection that might need drainage, IV antibiotics, or even hospital care.

When to see a regular doctor soon

Book a clinic or telehealth visit within a day or two if:

  • Sore throat and swollen tonsils last more than 3–5 days.
  • You have fever over 38–38.5°C (100.4–101.3°F) that isn’t improving.
  • You see white patches, pus, or a foul smell from your tonsils.
  • You get swollen tonsils frequently (several times a year).
  • You’re extremely tired, with big glands in your neck and armpits (possible mono).

A doctor can examine your throat, feel your neck glands, check your temperature, and do tests like a strep swab or blood tests if mono is suspected.

What you can do at home (for mild cases)

For mild symptoms while you arrange care, some supportive steps often help:

  • Drink plenty of fluids (water, warm tea, broths) to stay hydrated.
  • Use warm salt‑water gargles several times a day.
  • Try throat lozenges or sprays (if safe for your age).
  • Use acetaminophen or ibuprofen for pain/fever, if you have no allergies or contraindications and follow package or doctor dosing.
  • Rest and avoid smoking or secondhand smoke.
  • Soft, cool foods (yogurt, smoothies, ice pops) are usually easier to swallow.

These measures can ease discomfort but do not replace professional evaluation if symptoms are moderate or severe.

Why it matters to get the cause right

  • Viral tonsillitis usually improves on its own in about a week and doesn’t need antibiotics.
  • Bacterial tonsillitis (like strep) often does need antibiotics to reduce complications (such as rheumatic fever or kidney inflammation) and to shorten illness.
  • Recurrent or chronic tonsillitis, or structurally large tonsils that cause sleep problems (snoring, apnea), sometimes leads to a recommendation for tonsil removal.

Because the treatment differs, getting examined is important if you feel pretty bad, the swelling is large, or it isn’t improving.

Quick reality check for you

You should seek same‑day, in‑person care if you notice any breathing trouble, trouble swallowing saliva, severe one‑sided pain, or very high fever.

If your symptoms are mild (scratchy throat, slightly swollen tonsils, mild fever, can drink and swallow), it’s likely a viral infection or irritation, and home care plus a routine appointment if it doesn’t improve in a few days is reasonable.

Information gathered from public forums or data available on the internet and portrayed here.

This is general information only and not a diagnosis or a substitute for seeing a doctor. If you tell me your exact symptoms (fever or not, how long, one side or both, any white spots, your age), I can help you think through what to ask your doctor next.