Lung & Respiratory

What Is a Sore Throat? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Cathy Cassata
By Medically Reviewed by 
Reviewed:
Medically Reviewed
Pharyngitis, or sore throat, is the presence of inflammation in the back of the throat (also called the pharynx).

Pharyngitis can make it painful to swallow, and you may experience soreness, discomfort, pain, or scratchiness in the throat.
A sore throat is one of the most common reasons people visit a healthcare provider. Pharyngitis is often present because of an underlying cause, such as a cold, the flu, or mononucleosis ("mono"), each of which is caused by a virus. Sore throat subsides within a week or less most of the time. If a sore throat lasts for more than a week to 10 days, you should see your doctor.

Signs and Symptoms of a Sore Throat

Besides a sore or scratchy throat, symptoms accompanying pharyngitis may include the following:

  • Fever
  • Headache
  • Joint pain and muscle aches
  • Skin rash
  • Swollen lymph glands in the neck
But the symptoms vary, depending on the underlying cause of the sore throat. If the following symptoms are present, it's important to check in with your doctor, according to the American Academy of Otolaryngology–Head and Neck Surgery Foundation:

  • Prolonged sore throat (more than a week to 10 days)
  • Breathing difficulties
  • Swallowing difficulties or pain with swallowing
  • Difficulty opening the mouth
  • Swelling of the face or neck
  • Joint pain
  • Earache
  • Rash
  • Fever over 101 degrees F
  • Blood in saliva or phlegm
  • Lump in the neck
  • Hoarseness that lasts more than two weeks

Causes and Risk Factors of Sore Throat

Pharyngitis is caused by swelling in the pharynx, the anatomical structure that is between the tonsils and the larynx.

Sore throat is mostly caused by viral infections such as the common cold, the flu, mono, measles, chickenpox, and croup.

Sore throat can also be caused by coronaviruses, such as the virus that causes COVID-19.
Bacteria — such as group A strep, Bordetella pertussis (the cause of whooping cough), and the bacteria behind diphtheria — can sometimes cause pharyngitis.

The illness usually spreads between people by breathing in air that contains these organisms or by touching a surface with germs on it.

Other causes of a sore throat may include these factors and conditions:

Risk factors for sore throat include the following:

  • Cold and flu seasons
  • Having close contact with someone who has a sore throat or cold
  • Smoking or exposure to secondhand smoke
  • Frequent sinus infections
  • Allergies
  • Attending day care
  • Age (children and teens are more likely to develop sore throat or strep throat)
  • Weakened immunity due to conditions such as HIV or diabetes, or treatment with chemotherapy drugs or chronic steroids, which can lower resistance to infections

When a Sore Throat Is Chronic

Persistent throat pain that feels worse on one side may indicate a bacterial infection, which usually begins as a complication of tonsillitis or untreated strep throat (peritonsillar abscess).

In some cases, the pain may indicate an advanced tumor.

"A sore throat accompanied by a swollen neck gland should be seen by a physician soon," says Toribio Flores, MD, an ear, nose, and throat (ENT) specialist for the Cleveland Clinic's Head and Neck Institute at the Independence Family Health Center in Ohio.

Learn More About When a Sore Throat Is Considered Chronic

How Is Pharyngitis Diagnosed?

Diagnosing the underlying cause of a sore throat is key to determining how it should be treated.

Your doctor will most likely start by taking your medical history and then will give you a physical exam that may involve checking your temperature; looking at your throat, ears, and nose with a lighted instrument; checking your neck for swollen glands (lymph nodes); and listening to your breathing with a stethoscope.

Your healthcare provider may also take a throat culture or do a rapid strep test by taking a swab from your throat to be checked for the bacteria group A strep (the cause of strep throat).

Some clinics can get results right away, while others need to send the sample to a lab for testing.

If the rapid in-clinic test comes back positive, then you almost certainly have a bacterial infection (i.e., strep throat). If the test comes back negative, then you likely have a viral infection.

A blood test might be done to determine the cause of an infection.

If your doctor suspects that your sore throat is related to an allergy, you may be referred to an allergist for additional tests. If you experience chronic or frequent sore throat, you may be referred to an otolaryngologist (ENT doctor).

Prognosis of Sore Throat

In otherwise healthy people, a sore throat caused by a virus will generally go away on its own without complications.

A sore throat caused by bacteria, such as strep throat, needs to be treated effectively (see the Treatment section below) so that complications don't occur.

Duration of a Sore Throat

Most cases of pharyngitis subside within a week or less. If a sore throat lasts for more than a week to 10 days (the duration of a cold or the flu), and it's not associated with a known allergy or irritation, check in with your doctor.

Symptoms of sore throat due to a bacterial infection should ease within two to three days of starting treatment with appropriate antibiotics.

Treatment and Medication Options for Sore Throat

Your doctor may prescribe medications for a sore throat, depending on the underlying health condition causing it.

Medication Options

If your sore throat is associated with the flu, antiviral medicines may be effective.

Antiviral medications can shorten the length of the illness and make symptoms milder. They can also reduce your risk of flu complications, which is why these drugs are often recommended for people who are at a high risk, such as children, older adults, and people with certain preexisting conditions. Antivirals for influenza need to be started within 48 hours of symptom onset for the greatest impact.

Antivirals come in the form of pills, liquid medication, and inhaled medication. They prevent the virus from spreading in your body.

If your sore throat is caused by a virus, antibiotics won't help, and it will usually go away on its own within five to seven days. To reduce antibiotic resistance, it's important to take antibiotics only if your infection is caused by bacteria that require them.

Antibiotics can help if your sore throat is due to the following causes:
With strep throat, antibiotics are prescribed to prevent serious complications, such as rheumatic fever. (See the Complications section below).

Narrow-spectrum antibiotics are limited in the number of bacteria targeted by the drug and will not affect as many of the normal bacteria in the body. Guidelines from the Infectious Diseases Society of America recommend narrow-spectrum antibiotics such as penicillin. Penicillin is the treatment of choice for strep throat.

Amoxicillin is considered to be a broader-spectrum antibiotic, so it will kill more bacteria than penicillin.

Over-the-counter pain medications such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) can help ease symptoms. Children under 18 should not take aspirin; in children and teens with viral infections, it's been linked to Reye’s syndrome, a rare but serious condition that leads to swelling in the brain and liver.

Home Remedies for Sore Throat

The following home remedies may help soothe a sore throat:

  • Getting rest
  • Avoiding alcohol
  • Quitting smoking
  • Drinking warm liquids, such as lemon tea or tea with honey
  • Gargling with warm salt water (1/2 teaspoon of salt in 1 cup of water) throughout the day
  • Drinking cold liquids or sucking on fruit-flavored ice pops
  • Sucking on hard candies or throat lozenges (for adults only)
  • Running a cool-mist vaporizer or humidifier

Prevention of Sore Throat

Practicing good hygiene and reducing your exposure to the germs that cause sore throat can help prevent it. This includes the following guidance:

  • Wash your hands well; when soap and water aren't an option, use an alcohol-based hand sanitizer, ideally with at least 60 percent alcohol for maximal effect.
  • Do not share food, drinks, or utensils.
  • Cough or sneeze into a tissue, dispose of it, then wash your hands.
  • Clean surfaces you touch frequently such as telephones, TV remotes, and computer keyboards with sanitizer. If you travel, wipe down the phone and remote in your hotel room.
  • Maintain a physical distance from people you know are sick.
  • Keep any child diagnosed with strep throat out of school or day care until they've been on antibiotics for at least 24 hours and symptoms have improved.

Complications of a Sore Throat

Sore throat due to a viral infection doesn't generally lead to complications. But if your sore throat is due to a bacterial strep infection, the following complications can happen if the bacteria has spread:

  • Sinus infections
  • Ear infections
  • Abscesses near the tonsils
  • Swollen lymph nodes in the neck
  • Rarely, rheumatic fever (a heart disease) or acute kidney injury due to inflammation of the kidney (post-streptococcal glomerulonephritis)

Research and Statistics: Who Gets a Sore Throat?

Acute pharyngitis accounts for about 12 million outpatient visits annually, which is up to 2 percent of all outpatient visits, in the United States.

Approximately half of sore throats happen in childhood and adolescence. Among adults, most cases occur by age 40.

Approximately 1 in 10 adults with a sore throat has strep throat. Among children, 3 in 10 with a sore throat have strep.

COVID-19 and Sore Throat

Sore throat is one of the initial symptoms of COVID-19 that may appear 2 to 14 days after exposure to the coronavirus. COVID-19 shares many symptoms with the flu, and it can be difficult to tell the difference between the two based only on symptoms. But testing can confirm a diagnosis.

While people with mild cases of COVID-19 can isolate and recover at home, if you experience any of the following signs, the Centers for Disease Control and Prevention (CDC) urges you to seek emergency medical care:

  • Trouble breathing
  • Persistent pain or pressure in the chest
  • Confusion
  • Inability to wake or stay awake
  • Bluish lips or face
  • Coughing up blood or blood-tinged mucous

Related Conditions of Sore Throat

Sore Throat With a Cold or the Flu

Influenza, or the flu, and the common cold can be tricky to tell apart. Both are respiratory illnesses caused by viruses, and they share many symptoms, such as sore throat, which may be accompanied by cough, nasal congestion, sneezing, body aches, headache, and fever.

Common cold symptoms typically develop about one to three days after exposure to cold-causing viruses. Flu symptoms are typically more severe than those of the common cold.

Since colds and the flu are caused by viruses, rather than bacteria, antibiotics are not an effective treatment option. There is no cure for a cold, though over-the-counter medications may ease symptoms.

Learn More About Colds and the Flu

Strep Throat

Strep throat is a bacterial infection (caused by Streptococcus pyogenes, also known as group A strep) that is common in school-age children, but it’s not the most common cause of a sore throat. Viral infections are much more common.

The CDC estimates that there are several million cases of infection with group A strep bacteria in the United States each year.

Worldwide, strep throat affects as many as 616 million people each year.

Strep throat mostly affects children ages 5 to 15, but anyone can get it.

The symptoms of strep throat can overlap with signs of a viral infection, so it can be difficult to distinguish between the two. Besides sore throat, symptoms may include fever, swollen lymph glands in the neck, and exudate (a whitish covering) overlying the tonsils. If you have any of these symptoms along with a runny nose or a cough, it could be viral. The only way to tell if a person has strep throat is by a throat swab.

Learn More About Strep Throat

Resources We Love

ENThealth.org

Developed by the American Academy of Otolaryngology–Head and Neck Surgery Foundation, this site is a go-to when it comes to conditions involving the ear, nose, throat, and head and neck. ENT Health covers all the basics of sore throat, as well as related conditions, questions to ask your doctor, and how to find an ENT specialist.

Centers for Disease Control and Prevention

A trusted source, especially for info on infectious diseases, the CDC provides comprehensive, up-to-date coverage of the signs and symptoms, diagnosis, treatment, causes, and prevention of sore throat.

FamilyDoctor.org

This site, from the American Academy of Family Physicians, offers a wealth of medical advice for adults and children, including a section on sore throat. While it's no substitute for consulting with your healthcare provider, there's a Symptom Checker that allows you to select a symptom, answer several yes or no questions, and receive a possible diagnosis.

HealthyChildren.org

The American Academy of Pediatrics runs this site, a children's health source to find out how sore throat affects children, specifically, and when you should seek medical advice.

Additional reporting by Deborah Shapiro.

Editorial Sources and Fact-Checking

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