Overview
Tonsillitis is inflammation of the tonsils, two lymphoid tissues located at the back of the throat. It most often appears as part of an upper respiratory infection and is common in children and adolescents, though adults may be affected. While many people use the word interchangeably with pharyngitis or sore throat, tonsillitis specifically denotes involvement of the tonsils; pharyngitis refers to the pharynx and laryngitis to the larynx. For a concise summary see Tonsillitis overview.
Causes and mechanism
Tonsillitis can be caused by viruses or bacteria. Viral causes include common respiratory viruses; bacterial cases are frequently due to group A Streptococcus species, among others. The infection or inflammation produces swelling, redness and sometimes pus in the tonsillar tissue. General discussions of viral and bacterial aetiologies can be found at viral causes and bacterial causes, respectively. The process is an immune response in lymphoid tissue and is related to the role of tonsils in trapping pathogens that enter through the mouth or nose.
Symptoms and diagnosis
Common symptoms include:
- Sore throat and painful swallowing
- Red, swollen tonsils; sometimes with white exudate or spots
- Fever, headache and general fatigue
- Neck pain or swollen cervical lymph nodes
- Bad breath or altered voice
Doctors diagnose tonsillitis by medical history and physical examination of the throat. Specific tests can include rapid antigen detection or throat culture to identify group A streptococcus and blood tests when needed. For information on inflammation and infection mechanisms see inflammation and infection. The anatomical location of the tonsils is shown in many medical guides: tonsil anatomy.
Treatment and prevention
Treatment depends on cause and severity. Viral tonsillitis is managed with supportive care: rest, fluids, analgesics and throat soothing measures (saltwater gargles, lozenges). Bacterial tonsillitis confirmed as streptococcal often receives antibiotics to shorten illness, reduce transmission and prevent complications; general antibiotic information is available at antibiotics. Over-the-counter pain relievers ease discomfort; severe swelling or breathing difficulty may require urgent care.
Prevention centers on hand hygiene, avoiding close contact with infected people, and staying home while contagious. If symptoms include fever or prolonged malaise, medical advice is recommended. For common symptom guidance see headache resources, fever guidance and approaches to managing fatigue.
Complications, interventions and notable facts
Most cases resolve without lasting harm. Potential complications include peritonsillar abscess (quinsy), spread of infection, or, in rare untreated streptococcal disease, systemic complications. Recurrent or obstructive tonsillitis — for example when infections are frequent, or enlarged tonsils cause breathing and swallowing problems — may lead to surgical removal of the tonsils (tonsillectomy). Tonsillectomy has a long history and remains an effective option when conservative care fails.
When to seek care
Seek prompt medical evaluation for severe throat pain, difficulty breathing, inability to swallow liquids, high fever, or symptoms that persist or recur. Early testing and appropriate treatment reduce discomfort, limit spread to others, and help prevent rare but serious complications.