Strep throat is a bacterial infection in the throat and the tonsils. The throat gets irritated and inflamed, causing a sudden, severe sore throat.
Strep throat is caused by streptococcal (strep) bacteria. There are many different types of strep bacteria. Some cause more serious illness than others.
Although some people are quick to think that any painful sore throat is strep, sore throats are usually caused by a viral infection and not strep bacteria. A sore throat caused by a virus can be just as painful as strep throat. But if you have cold symptoms such as coughing, sneezing, or a runny or stuffy nose, you probably do not have strep throat.
The most common symptoms of strep throat are:
- A sudden, severe sore throat.
- Pain when you swallow.
- Fever over 101°F (38.3°C).
- Swollen tonsils and lymph nodes.
- White or yellow spots on the back of a bright red throat.
You may also have a headache and belly pain. Less common symptoms are a red skin rash, vomiting, not feeling hungry, and body aches.
Strep throat can be passed from person to person. When a person who has strep throat breathes, coughs, or sneezes, tiny droplets with the strep bacteria go into the air. These droplets can be breathed in by other people. If you come into contact with strep, it will take 2 to 5 days before you start to have symptoms.
Your doctor will do a physical exam, ask you about your symptoms and past health, and do a lab test such as a throat culture or rapid strep test.
A rapid test gives a result within about 10 minutes. But sometimes the test doesn't show strep even when it is present. A culture takes one or two days but is better at finding all cases of strep.
If the rapid strep test is positive and says that you do have strep, there's no need to do the throat culture.