Throat Infections
Viral or bacterial infections causing a sore, painful throat
Quick Facts
- Type: Throat (ENT) infection
- Common causes: Viruses, streptococcal bacteria
- Main symptoms: Sore throat, pain swallowing, fever
- Seek urgent care: Trouble breathing or swallowing, drooling, severe swelling
Overview
A throat infection is an infection of the pharynx, the tube at the back of the mouth, or of the tonsils, the two soft masses of tissue at the back of the throat. These infections are very common and are a frequent reason for missed school and work. Most throat infections are caused by viruses, such as those that cause the common cold, while a smaller number are caused by bacteria, most importantly streptococcus, the cause of strep throat.
Knowing whether a throat infection is viral or bacterial matters because it guides treatment. Viral infections clear up on their own and do not respond to antibiotics, whereas bacterial infections such as strep throat are treated with antibiotics to relieve symptoms and prevent complications. Most throat infections resolve within a week with simple care.
Symptoms
The main symptom is a sore throat, but other features help suggest the cause.
- Pain or scratchiness in the throat, often worse when swallowing
- Red, swollen tonsils, sometimes with white patches or pus
- Fever and chills
- Swollen, tender glands in the neck
- Headache and body aches
- Hoarse voice
Viral throat infections often come with cough, runny nose, and congestion, while strep throat tends to cause a more severe sore throat without cold symptoms, sometimes with stomach upset in children. The infection of mononucleosis can cause an especially severe and long-lasting sore throat with very swollen tonsils, marked tiredness, and swollen glands in the neck and elsewhere, and it may take several weeks to settle.
Causes
Throat infections are caused by germs that inflame the throat and tonsils.
- Viruses: the most common cause, including cold and flu viruses and the virus that causes mononucleosis ("mono").
- Bacteria: group A streptococcus causes strep throat; other bacteria are less common.
- Spread: germs pass through respiratory droplets from coughing and sneezing, and by touching contaminated surfaces and then the face.
Irritants such as smoke, dry air, allergies, and acid reflux can cause a sore throat that is not due to infection.
Risk Factors
- Young age, as throat infections are most common in children and teenagers
- Close contact with infected people, such as in schools and daycare
- The cold and flu seasons
- Exposure to tobacco smoke and other irritants
- A weakened immune system
- Frequent sinus infections or allergies
Diagnosis
A doctor diagnoses a throat infection from the symptoms and examination and may test for strep.
- Throat examination: looking at the throat, tonsils, and neck glands for redness, swelling, and pus.
- Rapid strep test: a quick swab of the throat that detects streptococcus within minutes.
- Throat culture: a swab grown in the laboratory to confirm bacterial infection when needed.
- Blood tests: used if mononucleosis or another cause is suspected.
Treatment
Treatment depends on whether the infection is viral or bacterial, but comfort measures help in both cases.
- Self-care: rest, plenty of fluids, warm drinks, saltwater gargles, and throat lozenges to soothe the throat.
- Pain and fever relief: acetaminophen or ibuprofen to ease soreness and lower fever.
- Antibiotics: prescribed for confirmed strep throat or other bacterial infections to relieve symptoms and prevent complications; finish the full course as directed.
- Treating the cause of irritation: humidifying dry air, avoiding smoke, and managing reflux or allergies.
Antibiotics do not help viral throat infections, which improve on their own within about a week.
Prevention
- Wash hands often and thoroughly, especially during cold and flu season
- Avoid sharing cups, utensils, and food with people who are unwell
- Cover coughs and sneezes and dispose of tissues promptly
- Avoid close contact with people who have a throat infection until they have been treated
- Avoid smoking and exposure to secondhand smoke
- Keep up to date with recommended vaccinations
When to See a Doctor
See a doctor if a sore throat is severe, lasts more than a few days, or comes with a high fever, a rash, white patches on the tonsils, or very swollen neck glands. Seek emergency care right away for:
- Difficulty breathing or swallowing
- Drooling or an inability to swallow saliva
- Severe one-sided throat swelling or a muffled voice
- A high fever with a stiff neck or severe illness
Frequently Asked Questions
Are most throat infections viral or bacterial?
Most throat infections are caused by viruses, such as cold and flu viruses, and clear up on their own. A smaller number are bacterial, mainly strep throat, which is treated with antibiotics. A throat swab can tell the difference when needed.
Do I need antibiotics for a sore throat?
Antibiotics only help bacterial throat infections like strep throat; they do not work for viral sore throats. A rapid strep test or throat culture helps decide. Most sore throats improve with rest, fluids, and pain relief within about a week.
How is strep throat different from a viral sore throat?
Strep throat tends to cause a sudden, severe sore throat with fever and swollen glands but usually without a cough or runny nose. Viral sore throats more often come with cold symptoms such as cough and congestion. A swab test confirms strep.
How can I soothe a sore throat at home?
Rest, drink plenty of fluids, sip warm drinks, gargle with warm salt water, and use throat lozenges. Acetaminophen or ibuprofen can ease pain and fever. A humidifier and avoiding smoke also help.
When is a throat infection an emergency?
Seek emergency care if you have trouble breathing or swallowing, are drooling or cannot swallow saliva, have severe one-sided throat swelling with a muffled voice, or have a high fever with a stiff neck. These can signal a serious infection.
References
- Centers for Disease Control and Prevention (CDC). Sore Throat (Pharyngitis).
- MedlinePlus, U.S. National Library of Medicine. Sore throat.
- Mayo Clinic. Sore throat — Symptoms and causes.
- American Academy of Otolaryngology-Head and Neck Surgery. Sore Throats.