Info Clinic

Sore Throat: Virus, Strep Throat, or Another Cause

A sore throat is most often viral and resolves within a week. We explain how streptococcal tonsillitis differs, when a swab is needed, and which signs cannot wait.

Doctor in a mask, safety glasses, and gloves carefully handles an instrument during a sore throat exam
Published: October 31, 2026 · Updated: October 31, 2026 · 3 min read

A sore throat is very common and usually resolves on its own within a week. Distinguishing an ordinary viral inflammation from tonsillitis that needs attention is helped not by intuition but by examining the throat and a few clarifying tests.

What lies behind a sore throat

The throat works like a finely tuned instrument. Inflammation disrupts this tuning, and there are several reasons for it.

Most often the cause is viral — a cold or flu — or smoking; only rarely is the pain caused by bacteria. Other causes include laryngitis, tonsillitis, streptococcal throat infection, and infectious mononucleosis.

Viral pharyngitis or streptococcal tonsillitis

Viral inflammation lasts a few days and resolves without specific intervention. A bacterial cause, primarily group A beta-hemolytic streptococcus, occurs much less often, but it is precisely this that requires medical supervision.

The symptoms are similar in both cases, so distinguishing them by sensation alone is difficult. Typical manifestations look like this:

Streptococcal tonsillitis starts acutely: chills, headache, joint aches, fever. The sore throat appears simultaneously, less often toward the end of the first day; a frequent and early symptom is enlarged and tender submandibular lymph nodes, and the febrile period lasts three to five days.

Tonsillitis: when the tonsils become inflamed

Tonsillitis is an infection of the palatine tonsils: they become red, swollen, and sometimes covered with purulent spots or whitish coatings. The clinical picture resembles a severe cold — sore throat, difficulty swallowing, high fever, headache, cough, ear pain, and a feeling of fatigue.

Based on the nature of the changes, catarrhal, follicular, and lacunar forms are distinguished. Symptoms usually disappear within three to four days, although they may last longer; tonsillitis itself is not contagious, but the infections that cause it are transmitted by airborne droplets.

Examination and when to see a doctor

The diagnosis is often made after taking a history and examining the throat. If the nature of the inflammation is unclear, a swab is taken from the posterior wall of the throat to determine whether bacteria caused the inflammation; for a prolonged course, a blood test for mononucleosis is added.

Isolation of streptococcus from the mucosa does not confirm the diagnosis, because healthy people can also be carriers. Swabs from the oropharynx and nose are also tested for the causative agent of diphtheria.

A scheduled visit to a family doctor is needed if the pain does not ease within a week or the throat hurts frequently. Other reasons include a feeling of a lump in the mouth or neck, a mouth ulcer lasting more than three weeks, and a sore throat in a child under five years old; high fever, dehydration, and weakened immunity require a more prompt visit.

Call 103 or 112 immediately if, along with a sore throat, breathing becomes difficult, swallowing is impossible, or drooling appears. Other reasons for urgent action: a whistling sound on inhalation, swelling inside the mouth and throat, difficulty opening the mouth, difficulty speaking, rapid deterioration of the condition.

Complications

Peritonsillar abscess — pus accumulates between the tonsil and the wall of the throat. Streptococcal tonsillitis can retain the pathogen in the body and trigger rheumatic diseases.

The list includes otitis, inflammation of the paranasal sinuses, purulent inflammation of the cervical lymph nodes, laryngeal edema, kidney damage, myocarditis, and endocarditis. Chronic tonsillitis, glomerulonephritis, and rheumatoid arthritis can also develop.

Who gets sick more often

Incidence increases in the cold season, especially in spring and autumn, and in newly formed groups: dormitories, children's institutions, military units. People with weak body resistance are more susceptible to acute tonsillitis.

This is reference material; the decision about examination is made by a doctor, not by text on a screen.

Sources

  1. Sore throat — NHS
  2. Tonsillitis — NHS
  3. Ангіна — Вікіпедія
  4. When to call 999 — NHS
  5. When to visit A&E — NHS

Update history

First publication.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer