Sore Throat: What It Could Be and What to Do

A sore, inflamed throat can be tonsillitis (inflammation of the tonsils), pharyngitis (inflammation of the pharynx), irritation from dry air, reflux, or smoke, or an allergic reaction. MedlinePlus states the base rate plainly: most sore throats are caused by viruses, not bacteria. Group A streptococcus, the one cause that antibiotics actually treat, accounts for about 5% to 15% of cases in adults and 15% to 30% in children.

Main causes of an inflamed throat

• Viral infection: the most common cause by a wide margin. It usually arrives with other cold or flu symptoms — runny nose, cough, hoarseness. Those three are the signature of a virus, not of strep.
• Group A strep: less common, but the one worth identifying, because untreated it can lead to rheumatic fever. It tends to bring sudden severe pain, fever, swollen neck glands, and pus on the tonsils — with no cough.
• Tonsillitis: inflammation centered on the tonsils, viral in roughly 70% to 95% of cases.
• Pharyngitis: inflammation of the pharynx, the throat wall around and behind the tonsils.
• Mononucleosis: an Epstein-Barr virus infection whose classic triad is fever, swollen glands, and tonsillar pharyngitis — often with visible exudate that looks exactly like strep.
• Irritation: dry air, cigarette smoke, pollution, or overusing your voice can inflame the throat with no infection at all.
• Laryngopharyngeal reflux: stomach contents reaching the larynx and pharynx. StatPearls notes that many people with LPR have no heartburn — the complaint is throat clearing, a lump-in-the-throat feeling, or hoarseness instead.
• Allergy: allergic rhinitis with postnasal drip irritates the throat continuously.

The four signs that actually shift the odds

American practice scores a sore throat rather than eyeballing it. The Centor criteria, in the modified (McIsaac) version used by the AAFP, give one point each for:

Criterion	Points
Absence of cough	1
Swollen, tender anterior neck lymph nodes	1
Temperature of 100.4 °F (38 °C) or higher	1
Tonsillar exudate or swelling	1
Age 3 to 14	+1
Age 15 to 44	0
Age 45 and older	−1

The total is a probability, not a diagnosis:

Score	Chance it is strep	What the AAFP review recommends
0 to 1	7% to 13%	No testing, no antibiotics
2 to 3	21% to 34%	Rapid antigen test (RADT)
4 to 5	50% to 69%	Rapid test, or empiric antibiotics

Read the top row twice. Even a perfect score leaves a coin-flip chance the throat is viral — which is why the next section exists.

Test before antibiotics, not after

The IDSA guideline is explicit: swab the throat and test by rapid antigen test and/or culture, because clinical features alone cannot reliably separate strep from a virus. Two practical consequences:

1. An obviously viral throat should not be tested. Cough, runny nose, hoarseness, and mouth ulcers point away from strep, and testing someone in that picture mostly finds carriers.
2. In children and teens, a negative rapid test gets a backup culture. The rapid test misses roughly 10% to 30% of cases in that age group, where strep is more prevalent. Adults don’t normally need the backup.

The scale of the miss is worth naming: the AAFP review reports that only about 10% of adults seeking care for a sore throat have strep, yet 60% or more leave with an antibiotic prescription.

What to do about an inflamed throat

1. Drink plenty of water and warm liquids, which help ease the discomfort.
2. Gargle with warm salt water, a comfort measure that can reduce irritation.
3. Rest your voice, avoiding talking a lot or shouting while your throat is inflamed.
4. Use pain relievers, as directed, to ease pain and fever. Children should not be given aspirin.
5. Avoid smoke and very dry environments, which worsen the irritation.
6. Get tested rather than requesting antibiotics if the picture is sudden severe pain with fever, swollen glands, pus, and no cough.

Warning signs that call for more urgent care

Seek medical care quickly if, besides the inflamed throat, there’s difficulty swallowing or breathing, excessive drooling (especially in children), significant neck swelling, a fever of 101 °F (38.3 °C) or higher that won’t come down, or symptoms that worsen instead of improving. Difficulty breathing with drooling and a muffled voice can mean epiglottitis, which is an emergency.

One trap deserves its own line: a sore throat with exudate that turns out to be mononucleosis and gets amoxicillin anyway produces a widespread maculopapular rash in up to 30% of people. It is not a penicillin allergy, but it is a reason the swab result matters.

This content is informational and does not replace medical consultation, diagnosis, or treatment. See in detail tonsillitis symptoms, pharyngitis symptoms, sore throat and fever, sore throat without pain, and white patches on the throat: what it could be.