What Is Strep Throat?
Key takeaways:
Strep throat is a highly contagious infection of the soft tissues in the throat. It’s caused by group A Streptococcus bacteria.
Strep throat is spread through respiratory secretions from coughing, sneezing, and saliva.
Strep throat is most common in children ages 3 to 15. It’s usually a minor illness, but it can sometimes cause serious complications.
Table of contents
Sore throats are common reasons for a visit to your primary care provider. Fortunately, most cases of sore throat go away on their own and aren’t anything to worry about. But a strep throat infection is different: It can sometimes result in serious complications.
Let’s take a closer look at what causes strep throat, along with how it’s diagnosed and treated.
What is strep throat?
Strep throat is a common bacterial infection of the tonsils and soft tissues at the back of the throat. It’s most often diagnosed in children, and it’s commonly seen in those ages 3 to 15. But sometimes adults get it too.
Most strep throat infections are minor illnesses. Some, though, can be very serious or develop complications.
What causes strep throat?
Strep throat is caused by bacteria called Streptococcus pyogenes, or group A Streptococcus (group A strep, or GAS). GAS is very contagious and easily spreads from person to person. Some of the ways you might pick up GAS bacteria are:
Being near an infected person when they laugh, cough, sneeze, talk, or sing
Having direct contact with respiratory secretions from an infected person
Drinking or eating after an infected person
Touching your nose, face, or mouth after touching an infected surface
Strep throat isn’t just a childhood illness. Adults are at risk too.
Penicillin and amoxicillin are the first-choice treatments for strep throat. But there are some alternatives if you can’t take penicillin or amoxicillin.
Can home remedies help strep throat? Yes, along with antibiotics, these at-home treatments can help you feel better faster.
How is strep throat diagnosed?
When you go to a healthcare professional for a sore throat, they’ll ask about your symptoms and do a physical exam to look for signs of strep throat. Some of the physical signs of strep throat include:
White patches on the tonsils
Red spots on the back of the throat
Red, swollen tongue
Swollen or tender lymph nodes in the neck
Rash at the bend of the elbow
Bad breath
Lack of a cough
These signs may point to strep throat. But you’ll probably still need a throat swab to confirm the diagnosis. A throat swab can be used for different tests:
Rapid strep test: Results are available in a few minutes.
Throat culture: Results take a few days.
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How do you treat strep throat?
Strep throat needs to be treated with antibiotics. The most common antibiotics used to treat strep throat are:
While you’re taking your antibiotics, you can follow some basic self-care techniques to feel better. Some things that might help include:
Nonsteroidal anti-inflammatory drugs (NSAIDs) — like ibuprofen — for fever and throat pain
Lozenges or honey to soothe your throat
Using a humidifier
Staying hydrated
Getting plenty of rest
Foods that are soft or easy to swallow (like ice cream, broth, applesauce, and Jell-O)
What happens if you don’t treat strep throat?
A strep throat infection isn’t usually serious and will likely go away on its own. But it’s recommended that you treat strep throat with antibiotics. That will help clear the infection to prevent some rare and potentially life-threatening complications.
Serious complications of strep throat include:
Peritonsillar abscess: collection of pus behind the tonsils
Retropharyngeal abscess: collection of pus behind the throat
Mastoiditis: infection of the mastoid bone behind the ear
Acute rheumatic fever: inflammation of the heart, joints, and brain
Post-streptococcal glomerulonephritis: kidney disease
PANDAS: short for pediatric autoimmune neuropsychiatric disorders associated with strep infections, which is extreme neurological or behavior changes
How long are you contagious with strep throat?
You’re still contagious for about 12 to 24 hours after starting antibiotics for strep throat. Typically, you’ll start to feel better in that time frame. A person who has untreated strep throat may be contagious for up to 3 weeks. Treatment with antibiotics reduces the risk of spread by shortening the time a person is contagious.
How can you prevent strep throat?
Strep throat is highly contagious. Taking steps to stop its spread can protect people at greatest risk. Here are some of the things you can do to prevent strep throat:
Cover your coughs and sneezes with a tissue or your bent elbow.
Wash your hands often.
If you’re infected, wear a mask around other people or avoid being around others.
Don’t share drinking glasses or utensils with others.
Wash glasses and utensils with hot water and dish soap.
If you’ve been prescribed antibiotics, make sure you finish them.
Unfortunately, there’s no vaccine or medication to prevent strep throat. Being diligent about personal hygiene is the most effective way to prevent illness.
Frequently asked questions
Yes, strep throat can go away on its own, without antibiotic treatment. It can take about 5 days for strep to go away without antibiotics. But when left untreated, strep can take much longer to go away. And you may be at risk of serious complications.
In general, strep throat shouldn’t be left untreated. Antibiotics reduce the risk of complications. They also limit the spread of infection and help you feel better more quickly. Most healthcare professionals will recommend treating strep throat for these reasons.
No, strep throat isn’t considered a sexually transmitted infection (STI). A strep throat infection is mainly spread through respiratory droplets — not sexual activity.
The bottom line
Strep throat is a common throat infection. It’s highly contagious and spread by respiratory fluids from an infected person. Children between ages 3 and 15 are most commonly affected. But it can sometimes infect adults too.
Strep throat is almost always a minor illness. Rarely, though, it can have serious, life-threatening complications. Antibiotics are the preferred treatment for strep throat to clear the infection, reduce its spread, and prevent complications.
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References
Centers for Disease Control and Prevention. (2024). About group A strep infection.
Centers for Disease Control and Prevention. (2024). About strep throat.
Centers for Disease Control and Prevention. (2024). Clinical guidance for group A Streptococcal pharyngitis.
Centers for Disease Control and Prevention. (2024). Preventing group A strep infection.
Centers for Disease Control and Prevention. (2024). Testing for strep throat or scarlet fever.
Ebell, M. H., et al. (2024). Diagnosis of streptococcal pharyngitis. American Family Physician.
Thompson, K. M., et al. (2018). The shock of strep: Rapid deaths due to group A Streptococcus. Academic Forensic Pathology.
Walker, M. J., et al. (2014). Disease manifestations and pathogenic mechanisms of group A Streptococcus. Clinical Microbiology Reviews.
