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Strep throat is a bacterial infection in the throat and the tonsils. The throat and tonsils get irritated, inflamed, and painful, 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. Strep throat is most often caused by group A beta-hemolytic streptococcus (GABS). Groups C and G strep bacteria also can infect the throat.
Strep throat can be passed from person to person. When a person infected with strep throat breathes, coughs, or sneezes, tiny droplets with the strep bacteria go into the air and are breathed in by other people. If you come into contact with strep, it will take 2 to 5 days before symptoms start.
The most common symptoms of strep throat are a sudden and severe sore throat, pain when you swallow, and fever. Other symptoms include swollen tonsils and lymph nodes and white or yellow spots on the back of a bright red throat. You may also have a headache and belly pain.
Your doctor will examine you, ask about your symptoms, and do a lab test. This may be a throat culture or a different type of test (called a molecular test) that looks for DNA (the genetic information inside of cells). A molecular test looks for the most common type of bacteria that can cause a throat infection.
To do a throat culture or a molecular test, the doctor will swab a sample of cells from the back of your throat. The throat culture sample will go into a special cup (culture) where the strep bacteria can grow over time. If strep bacteria grow, the doctor knows that you have strep. Another type of test is called a rapid strep test. You can’t get this test through an Alberta Health Services lab or service. You may be able to buy this test at your local pharmacy. If the doctor does a rapid test and the test says that you don't have strep (the test is negative) but your symptoms suggest that you do, your doctor may want to do a throat culture or a molecular test to be sure. This is because rapid strep tests sometimes show you don't have a throat infection when you actually do. If the rapid strep test is positive and says that you do have strep, there's no need to do the throat culture or a molecular test.
Strep throat is treated with antibiotics. These drugs shorten the time you're able to spread the disease, and they lower the risk of spreading the infection to other parts of your body. Antibiotics may help you feel better faster. Taking an over-the-counter medicine like acetaminophen can help relieve pain and reduce fever.
Try the following ideas to help prevent strep throat.
Wash your hands often when you are around people with colds or viral or bacterial illnesses.
Eat a good diet, get plenty of sleep, and exercise regularly. Managing stress can also strengthen your body's ability to fight off illness, such as strep throat.
Try this during the dry winter months or year-round if you live in a dry climate. Moisture in the air (humidity) helps keep your mucous membranes moist and more resistant to bacteria. You can use a humidifier in the bedroom while you sleep. But use care if a person in the home has asthma or allergies, because mould or other particles that collect in the humidifier can make these conditions worse. Follow the directions for cleaning the machine.
Smoke irritates the throat tissues and may make you more likely to get an infection.
The most common symptoms of strep throat are:
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 can be passed from person to person. If you come into contact with the strep bacteria, it will take 2 to 5 days before you start to have symptoms.
Symptoms of strep throat most often start within 2 to 5 days after you come in contact with someone who has a strep infection. Strep throat most often goes away in 3 to 7 days with or without antibiotic treatment.
If strep throat isn't treated with antibiotics, you can still spread the infection for 2 to 3 weeks even if your symptoms go away. If you start antibiotics, within 24 hours you are much less likely to spread the infection. With antibiotics, you also are less likely to get other problems from the strep infection.
Problems (complications) from strep throat are rare. But they can occur, especially if your throat infection isn't treated with antibiotics. Problems can occur when the strep infection spreads to other parts of the body. This can cause other infections, such as an ear or sinus infection or an abscess near the tonsils (peritonsillar abscess). Problems can also cause your immune system to attack itself. This can cause serious conditions such as rheumatic fever.
Treating strep throat can greatly reduce your risk for rheumatic fever and problems related to this fever. It's not clear whether treating the strep infection with antibiotics lowers your risk for inflammation of the kidneys (acute glomerulonephritis).
Call 911 or other emergency services immediately if you:
Call your doctor now if you have:
Call a doctor if the following symptoms develop 2 to 3 weeks or longer after a strep throat infection. These symptoms may be a sign of rheumatic fever.
Call your doctor if your symptoms don't improve after 2 days of treatment with an antibiotic.
Watchful waiting is a good choice if your sore throat occurs with symptoms like those of a cold, such as sneezing, coughing, and a runny or stuffy nose. In general, the more of these symptoms you have, the less likely it is that your sore throat is caused by a strep infection. You can try home treatment if your sore throat isn't severe and you have other symptoms of a cold.
Your doctor will examine you, ask about your symptoms, and do a lab test, such as a throat culture or molecular test. Sometimes a rapid strep test is used to check for strep. Your doctor may confirm the results of the rapid strep test with a throat culture or a molecular test.
A throat culture can find strep bacteria. A culture takes 1 or 2 days, but it's better at finding all cases of strep. A sample of cells from the back of your throat is added to a substance that promotes the growth of bacteria. If no bacteria grow, the culture is negative. If strep bacteria grow, the culture is positive.
A molecular test looks for DNA of the most common type of bacteria that cause a throat infection. A rapid strep test analyzes the bacteria in your throat to see if strep is causing your sore throat. The doctor uses a cotton swab to gather cells from the back of your throat for testing. This test gives results within about 10 minutes. But sometimes it doesn't show strep even when you have strep. The rapid strep test is not used often in Canada. It’s also not available through Alberta Health Services. You may be able to buy it at your local pharmacy. A negative rapid strep test result can mean there are no strep bacteria present. But the rapid strep test can give negative results even when strep bacteria are present (false-negative test results). If the rapid strep test result is negative but strep throat is still suspected, your doctor may send you for a throat culture or a molecular test to verify the results. If the rapid strep test result is positive, a throat culture or a molecular test isn't needed. Antibiotic treatment can be started right away. Antibiotics may not make you well faster. But they shorten the time you are able to spread the disease to others. Antibiotics also lower the risk of spreading the infection to other parts of your body.
Doctors usually treat strep throat with antibiotics. These drugs shorten the time that you're able to spread the disease to others (are contagious). And they lower the risk of spreading the infection to other parts of your body. They also may help you feel better faster.
You are contagious while you still have symptoms. Most people stop being contagious 24 hours after they start antibiotics. If you don't take antibiotics, you may be contagious for 2 to 3 weeks, even if your symptoms go away.
Your doctor may also advise you to take an over-the-counter medicine like acetaminophen (such as Tylenol) or ibuprofen (such as Advil or Motrin) to help with pain and lower your fever. Be safe with medicines. Read and follow all instructions on the label. Don't give aspirin to anyone younger than 18. It has been linked to Reye syndrome, a serious illness.
Your doctor may have prescribed an antibiotic for strep throat. Take all of the antibiotic exactly as prescribed. This will help prevent the infection from coming back and will prevent complications of infection that could occur if you do not take the medicine as prescribed.
There are many ways that you can make yourself feel better while you are waiting for the strep infection to go away.
Drink plenty of fluids and increase humidity (moisture in the air) in your home to help keep your throat moist. Herbal teas formulated for colds may help relieve symptoms.
Stay home the first day of antibiotic treatment. You are still contagious and might pass the infection to others. Rest in bed if you feel very sick. Bedrest is not required if you feel fine.
For the first 24 hours after you start taking an antibiotic, you are still contagious. You can avoid passing the strep throat infection to others and reinfecting yourself by:
Adaptation Date: 8/17/2023
Adapted By: Alberta Health Services
Adaptation Reviewed By: Alberta Health Services
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