What Causes Sore Throat and Strep Throat?

Strep throat is an infection in your throat and tonsils. With strep throat, your tonsils become inflamed. This inflammation usually affects the surrounding area of your throat as well, which causes your sore throat.

Strep throat seldom causes more serious illnesses such as rheumatic fever, a disease that can create permanent damage to your heart and heart valves. It is important to see a healthcare provider for a prompt diagnosis and treatment. With proper treatment, your strep throat should be resolved within 10 days.

How Common is Strep Throat?

Healthcare providers treat more than 616 million new cases of strep throat around the globe each year. Strep throat is the primary cause of sore throat in adults and children. The condition is responsible for up to 15% of new cases of sore throats in adults in the U.S each year. It accounts for up to 35% of new cases of sore throat in children.

Who Does Strep Throat Affect?

Strep throat is most common in children between the ages of 5 and 15. It can also affect siblings, parents, teachers, and other caregivers who have direct contact with a school-aged child.

People in group settings have a higher risk of getting strep throat. Group settings can include households, daycares, schools, including colleges, and military barracks.

Key Causes and Transmission Factors

Strep throat is quite contagious. People with the infection may not have symptoms or look sick. But even if you do not have symptoms, you can still easily spread the infection.

Strep throat spreads easily from person to person, especially among those in the same household. You can spread the bacteria that cause strep throat to other people through respiratory droplets and direct contact.

Bacteria- Group A Streptococci bacteria infect the throat and tonsils.
Respiratory Droplets- Sneezing or coughing spreads the bacteria.
Direct Contact- Sharing utensils, cups, or touching surfaces with bacteria and then touching your face.
Close Quarters- High transmission rates in schools, daycare centers, and households.
Common cold.
Flu, or influenza.
Mono, also called mononucleosis.
Measles.
Chickenpox.
Coronavirus disease, COVID-19.
Croup- A common childhood illness that causes a harsh, barking cough.

Other Causes

Other causes of a sore throat include:

Allergies- Allergic reactions can cause a sore throat. The reaction can be to mold, dust, pollen, or flecks of skin shed by dogs, cats, and other animals. Mucus that builds up and drips down the back of the nose and throat, or postnasal drip, can make a sore throat worse.
Dryness- Dry indoor air can make your throat feel rough and scratchy. Breathing through the mouth can also cause a dry, sore throat.
Irritants- Irritants in outdoor and indoor air, also called air pollution, can cause a sore throat. These include tobacco smoke, chemicals and dust, pollen, and mold. Chewing tobacco, drinking alcohol, and eating spicy foods can also irritate the throat.
Muscle strain- Yelling, talking loudly, or talking for a long time can strain muscles in the throat.
Gastroesophageal reflux disease (GERD)- GERD causes stomach acid to back up in the food pipe, also called the esophagus.
HIV infection- A sore throat and other flu-like symptoms sometimes appear after someone is infected with HIV. Someone who is HIV-positive might have a constant sore throat.
Tumors- Cancerous tumors of the throat, tongue, or larynx can cause a sore throat. Other symptoms may include hoarseness, trouble swallowing, noisy breathing, a lump in the neck, or bloody mucus.