Tonsils, Immunity, and Tonsillitis: What They Do, Why They Swell, and How to Treat Them

Your tonsils are not useless lumps. They sit where air and food first meet your immune system, catching germs and teaching your body what to fight. That mission is why they sometimes flare up and hurt like mad. If you’ve had a sore throat you can’t shake, or a child who keeps getting them, you want straight answers-what tonsils do, how to tell viral from strep, when antibiotics help, and when surgery actually makes sense.

TL;DR:

• Tonsils are immune “sentinels” that sample germs; most sore throats are viral and don’t need antibiotics.
• Strep throat is more likely with fever, swollen tender neck nodes, tonsil exudate, and no cough; confirm with a rapid test or culture.
• Home care (pain relief, fluids, rest) is first-line; antibiotics help confirmed strep and cut complications.
• Consider tonsillectomy if infections are frequent and well documented or if breathing/sleep is affected.
• See urgent care for red flags: trouble breathing, drooling, severe one-sided throat pain, dehydration, or rash with fever.

What Your Tonsils Actually Do (and When They Backfire)

Think of tonsils as front-door bouncers for your immune system. The palatine tonsils (the ones you can see), plus adenoids (behind the nose) and lingual tonsils (base of tongue), form a ring of immune tissue called Waldeyer’s ring. They’re packed with immune cells-B cells, T cells, dendritic cells-that sample incoming viruses and bacteria. Specialized surface cells pull germs inside where lymphoid follicles build “most wanted” posters (antibodies) that teach your body what to do next time.

This work matters most in childhood. Tonsils are relatively larger and more active when kids first meet the world’s germs. After puberty, tonsils usually shrink a bit and the rest of your immune system takes over more of the load. That’s why kids catch more throat bugs and adults tend to get fewer-but not none.

Here’s the catch: exposure and training can trigger inflammation, swelling, and pain. That’s tonsillitis. Sometimes the immune response gets messy-bacteria can take advantage, or pus can collect near a tonsil and form a peritonsillar abscess, which needs urgent care.

Do you “need” your tonsils forever? Guidelines from the American Academy of Otolaryngology-Head and Neck Surgery say removing tonsils for the right reasons doesn’t break your immune system. Studies tracking kids after tonsillectomy find no meaningful long‑term immune deficit. You might see a short bump in respiratory infections while healing, but your broader immune network-lymph nodes, spleen, mucosal immunity-keeps doing the job.

Spotting Tonsillitis: Symptoms, Causes, and What’s Contagious

Tonsillitis just means the tonsils are inflamed. The cause is what matters.

• Viral causes (most common): rhinovirus, adenovirus, influenza, RSV, enteroviruses, and Epstein-Barr virus (mono). These don’t need antibiotics.
• Bacterial causes: the big one is Group A Streptococcus (Strep A). Less common: Groups C and G strep, Mycoplasma.

How common is strep? CDC data: roughly 20-30% of sore throats in children and 5-15% in adults are Strep A. The rest are viral. That’s why testing and smart symptom read‑outs matter.

Classic strep clues (the Centor/McIsaac criteria):

• Fever
• Tender anterior neck nodes
• Tonsillar exudate (white/yellow coating)
• No cough
• Age adjustments (kids more likely than older adults)

Viral clues: cough, runny nose, hoarseness, conjunctivitis, mouth ulcers. Mono tends to bring big fatigue, swollen spleen, and very sore throat that lingers.

Contagiousness: Viral infections spread from a day before symptoms to a few days after. Strep spreads via droplets; once on antibiotics, people are typically far less contagious after 24 hours and can return to school or work if fever‑free and feeling okay. Without antibiotics, strep can linger and spread longer.

Red flags that hint at something more serious:

• Trouble breathing, drooling, or stridor (airway risk)
• Severe one‑sided throat pain, muffled “hot‑potato” voice, or jaw spasm (possible peritonsillar abscess)
• Neck stiffness, severe headache, or a spreading neck swelling
• Dehydration (no urination for 8-12 hours, very dry mouth, lethargy)
• Fever lasting beyond three days despite home care

Local twist (Aotearoa New Zealand): Certain communities-Māori and Pacific peoples, especially in crowded housing-carry higher risk of rheumatic fever from Strep A. Here, sore throat management can be more aggressive in children and teens: prompt testing and sometimes empiric antibiotics while awaiting results, as guided by local health pathways. If that’s your whānau, ask your GP or nurse what plan fits you.

Smart Treatment: From Home Care to Antibiotics to Surgery

Think steps, not guesswork. Here’s a clean way to approach it.

1. Start with comfort care. Most sore throats improve on their own in 3-5 days. Good care makes those days bearable and prevents dehydration.

   • Pain relief: paracetamol (acetaminophen) or ibuprofen in standard doses. Avoid aspirin in kids and teens.
   • Fluids: warm teas, broths, water. If swallowing hurts, sip often and use icy treats.
   • Honey (over 1 year old): calms cough and throat irritation.
   • Gargles: warm saltwater a few times daily. Lozenges if age‑appropriate (watch choking risk).
   • Humidify the room; avoid smoke and irritants.
   • Rest. Your body heals faster when you sleep.

2. Use a strep score and test when it counts. The Centor/McIsaac score helps decide who needs a rapid test or culture.

   • Score 0-1: likely viral; no test needed unless high‑risk setting.
   • Score 2-3: do a rapid antigen test; culture if negative in children/teens.
   • Score ≥4: high chance of strep; testing and clinician review. In some clinics, antibiotics may start if testing isn’t available, especially for high‑risk kids.

   NICE (UK) sore throat guidance and CDC recommendations align: don’t hand out antibiotics without evidence. In NZ high‑risk communities, your clinician may test and treat more readily to prevent rheumatic fever.

3. Antibiotics: when they help and when they don’t. They help confirmed strep. They don’t help viral infections, and they can cause side effects.

   • First‑line: penicillin V or amoxicillin for 10 days. Strep A remains sensitive to penicillin.
   • Penicillin allergy (non‑anaphylactic): cephalexin.
   • Severe allergy: azithromycin or clindamycin (note resistance patterns vary; your clinician will choose).
   • Benefit: symptoms shorten by about 16 hours on average (Cochrane Review) and reduce risks like peritonsillar abscess and rheumatic fever.
   • Contagiousness: after 24 hours on antibiotics, most people aren’t shedding enough to spread.

4. Consider a single dose steroid for severe pain. A one‑off dose of dexamethasone prescribed by a clinician can cut pain and help swallowing within 24-48 hours. Not for everyone; it’s a shared decision.

5. When does surgery help? Tonsillectomy isn’t a quick fix for the odd sore throat. It’s for specific patterns:

   • Recurrent, well‑documented infections that hit the “Paradise” criteria: 7 in one year, 5 per year for 2 years, or 3 per year for 3 years-each with fever, swollen nodes, exudate, or positive strep test recorded.
   • Obstructive sleep‑disordered breathing: big tonsils causing snoring, pauses in breathing, restless sleep, daytime behavioral issues in kids, or sleep apnea in adults.
   • Complications: recurrent peritonsillar abscess, or one tonsil growing larger than the other with concerns that need specialist review.

   Benefits: fewer infections and better sleep when criteria are met. Trade‑offs: pain for 1-2 weeks, bleeding risk (~1-5%, higher in adults), bad breath while healing, time off school or work. Most kids bounce back in 7-10 days; adults can take longer.

Pro tip: keep a throat diary. Note date, fever, test results, days missed, and meds. If you ever need to discuss surgery, that record is gold.

Quick Tools: Checklists, Decision Aids, and FAQs

Use these to make faster, safer choices at home and in clinic.

“Is it likely strep?” quick score

• Fever? +1
• Tender front neck nodes? +1
• Tonsil exudate? +1
• No cough? +1
• Age 3-14? +1; 15-44? 0; 45+? −1

0-1: viral likely; 2-3: test; 4-5: test and clinician review, consider treatment per local guidance.

Home‑care checklist

• Set pain relief reminders (don’t chase pain; stay ahead).
• Fill a 1-2 litre water bottle and finish it through the day (kids need smaller goals).
• Warm saltwater gargle after meals and before bed.
• Honey lemon drink (if over age 1) or ice pops for comfort.
• Cool‑mist humidifier on at night; fresh air in the day.
• Rest; skip hard workouts until fever settles.

When to see a clinician

• High strep score, or symptoms not improving after 3-5 days
• Severe pain, drooling, or trouble opening the mouth
• Rash with fever (possible scarlet fever)
• Breathing pauses during sleep or loud nightly snoring in a child
• Frequent documented infections meeting or nearing surgery criteria

Decision aid: tonsillectomy yes/no

• Count: Do you meet 7/5/3 Paradise thresholds with proper documentation?
• Impact: Have infections caused major school/work absences or hospital visits?
• Sleep: Are there signs of obstructive sleep issues?
• Risk: Any bleeding disorders or medical conditions that change surgical risk?
• Timing: Can you plan the 2‑week recovery window safely?

Mini‑FAQ

• Can adults get tonsillitis? Yes. It’s less common than in kids but often hits harder, and recovery from surgery takes longer in adults.
• Do antibiotics make sore throats go away fast? For strep, they shave about 16 hours off symptoms on average and prevent complications. For viral infections, they don’t help.
• What about mono? Big fatigue, swollen glands, and a sore throat that lingers. Avoid contact sports for a few weeks because of spleen swelling; antibiotics won’t help.
• Are steroid mouthwashes or sprays useful? Some clinicians use a short course of topical steroids for severe inflammation. A single dose of oral dexamethasone has the best evidence for acute sore throat pain relief.
• Will my child get sick more without tonsils? Most research shows no meaningful long‑term hit to immunity. Some kids actually get sick less because sleep improves and infections drop.
• Do tonsils grow back? Tiny regrowth can happen, especially in very young children, but full regrowth is uncommon.
• How soon can my child return to school after strep? Usually after 24 hours of antibiotics, fever‑free, and feeling better.

Next steps and troubleshooting

• Parent of a child with frequent sore throats: Start a symptom log now. Ask your GP about the local approach to strep testing, especially if your whānau is in a higher‑risk group for rheumatic fever. Discuss sleep: snoring, pauses, mouth breathing, daytime behavior.
• Adult with repeat infections: Bring documentation. Ask about a culture if rapid tests keep being negative but symptoms are classic. If you smoke or vape, this is the moment to cut back-it slows healing.
• Student with a sore throat before exams: Hydrate, schedule pain relief, and ask a clinician about a single dose steroid for severe swelling if appropriate. Push sleep, not caffeine.
• Post‑tonsillectomy at home: Stay ahead of pain with the plan you were given, keep drinking even if it hurts, watch for fresh bleeding, and call your surgical team if you see it.

Credibility snapshot

• Strep prevalence and testing: CDC clinical guidance (updated through 2024).
• Antibiotic benefit: Cochrane Review on antibiotics for sore throat (most recent update shows ~16‑hour average symptom reduction for confirmed strep).
• Tonsillectomy indications: American Academy of Otolaryngology-Head and Neck Surgery guideline (Paradise criteria), with updates through 2019 and widely used in 2025.
• UK primary care approach: NICE sore throat assessment and management guideline (latest updates 2023-2024).
• NZ context on rheumatic fever risk and sore throat management: Te Whatu Ora public health programmes and primary care health pathways (2025).

One last nudge: sore throats are common, but the pattern over time tells the real story. Keep notes, treat the pain, test when the signs point to strep, and save surgery for the situations where it clearly helps. That balance keeps you (and your kids) healthier and out of waiting rooms.