What Causes a Sore Throat?

A wide array of conditions can cause your throat to randomly start hurting, from infections to allergies to acid reflux and, rarely, tumors. Pain is just one symptom of what's typically known as a sore throat (pharyngitis). Other symptoms include having a dry or scratchy feeling in your throat or trouble swallowing.

Chances are your sore throat will fade in a few days without any real prodding. Decongestants, pain relievers, and saline nasal sprays can help in some cases. A healthcare provider may advise other treatments, such as antibiotics, depending on the cause.

1. Viral Infections

Viruses are one of the most common causes of sore throats. A sore throat is often a symptom of a cold or the flu. Viruses that cause mononucleosis, measles, chickenpox, croup, and other illnesses can also produce sore throats. The SARS-CoV-2 virus that causes COVID-19 can also produce a sore throat.

A sore throat can sometimes appear as an early sign of human immunodeficiency virus (HIV). Many people with HIV have flu-like symptoms within two to four weeks of infection.

Try some of the following remedies to treat a sore throat caused by a virus:

• Gargle with warm salt water.
• Stay hydrated.
• Try over-the-counter (OTC) pain relievers, like Tylenol (acetaminophen) or Advil (ibuprofen).
• Use a humidifier or steamer to ease respiratory symptoms.

Most viral infections tend to go away in about a week, except for mononucleosis, which can last weeks or months. Protect yourself from viral infections by washing your hands well and often. Don't get too close to people who are sick, and cover your coughs and sneezes.

2. Bacterial Infections

It's less common, but bacterial infections can also cause a sore throat. You may develop a sore throat if you contract a bacteria through direct exposure to respiratory droplets from an infected person (coughing, sneezing), by kissing, or from intimate contact. A healthcare provider can prescribe antibiotics to treat bacterial infections.

3. Sinus Infections

A sinus infection, or sinusitis, is inflammation or swelling of the tissue that lines the sinuses. It's caused by bacteria, fungi, or viruses. You may develop a sore throat with a sinus infection as a result of post-nasal drip. Post-nasal drip happens when excess mucus builds up and trickles down the back of your throat.

Other sinus infection symptoms can include:

• Bad breath 
• Cough that worsens at night
• Fatigue or general ill feeling
• Fever
• Headache
• Loss of smell
• Pressure or pain behind your eyes 
• Runny or stuffy nose
• Toothache

A healthcare provider can prescribe antibiotics for a sinus infection caused by bacteria. Decongestants, pain relievers, and saline nasal sprays can also help relieve symptoms.

4. Allergies

About 50 million people in the United States have allergies. Allergies happen when your body has an outsize reaction to specific foreign invaders like:

• Dust
• Mold
• Pet dander
• Pollen

These invaders set off a cascade of symptoms, including a sore throat. Other symptoms include sneezing and a stuffy nose. Sore throats from allergies can be made worse by post-nasal drip.

Some people may confuse allergy-related sore throats with viral and bacterial sore throats. Allergies tend to cause symptoms like a runny nose and itchy eyes rather than a fever. Many allergy-related sore throats also only appear during certain seasons, like spring, summer, or fall.

5. Acid Reflux

A sore throat can be a symptom of acid reflux, especially if it's chronic, like gastroesophageal reflux disease (GERD). GERD is a digestive disorder in which stomach acid comes up in the esophagus.

Symptoms, which can get worse after a big meal, also include:

• Chest pain
• Cough
• Heartburn
• Hoarseness
• Nausea

There are medications to treat GERD. You can also tame the condition by managing your weight and eating dinner two to three hours before bed.

6. Irritants

Irritants differ from allergies but also cause reactions to certain outside elements, like air pollution or cleaning products. Exposure to certain irritants can make your throat sore, so it's best to try to avoid them if you can.

7. Laryngitis

Laryngitis is inflammation and swelling of the larynx, which is also known as the voice box. Allergies, bacteria or viruses, and GERD can cause laryngitis. You may develop a sore throat, as well as a fever, hoarse voice, and swollen lymph nodes in the neck.

Antibiotics can treat laryngitis that's caused by a bacterial infection. It's important to rest your voice to decrease inflammation. Using a humidifier can add moisture to dry air, which also eases a sore throat.

8. Strep Throat

Strep throat, which is caused by Streptococcus bacteria, is a common culprit of sore throats, especially in children. Other symptoms may include:

• Chills
• Fever
• Red spots or white patches on the tonsils

A throat culture will tell you whether you have the infection. It's essential to treat strep throat if you have it. Late complications include damage to the kidneys and heart valves. Antibiotics, like penicillin and amoxicillin, usually clear strep throat.

9. Tonsillitis

Tonsillitis is inflamed and swollen tonsils. A viral or, more commonly, bacterial infection usually causes tonsillitis. The tonsils are two growths at the back of the throat that form the frontline of the body's immune system. They keep germs from entering the body.

Tonsillitis may cause a sore throat, as well as symptoms like:

• Chills
• Ear pain
• Fever
• Headache
• Pain when you swallow
• Red, swollen tonsils
• Tender jaw or throat 
• White or yellow patches on the tonsils

Tonsils can become large enough to obstruct the nasal passages in severe cases. You may experience breathing, swallowing, and sleep difficulties if that happens.

10. Throat Cancer

Throat cancer doesn't need to be at the top of your list of things to worry about when you have a sore throat, but it can happen. A tumor typically manifests with other symptoms, such as:

• A lump in your neck
• Trouble swallowing
• Ringing or pain in your ear

Throat pain from a tumor also tends to linger. It's important to see a healthcare provider right away if you have any of these red flags.

Is a Sore Throat Hereditary?

Sore throat has several potential causes. Some of these may be more common among people with certain genetic factors. Repeated bouts of strep throat and tonsillitis, for example, may run in families. The same is true for allergies and GERD.

Who Gets a Sore Throat?

Viral infections, which are the most common cause of sore throat, are generally more common in children. Even adults have an average of two or three colds per year.

You can't wholly keep viruses, allergies, or other causes of sore throats at bay. You can still help prevent sore throats by trying some of the following:

• Avoiding close contact with people who are sick
• Avoiding smoke exposure
• Not touching your eyes, nose, or mouth with unwashed hands
• Practicing proper handwashing
  

Risk Factors

Anyone can get a sore throat. It's most common in the colder months when viral infections like the cold and flu spread more easily. Certain risk factors, such as environmental pollutants, smoking, and a weak immune system, can also increase your likelihood.

Dry Air

Humidity and temperature can both affect the mucous membranes that line your throat. Dry air, for example, can cause discomfort. Summer air conditioning can have a similarly painful effect on your throat. This discomfort tends to be worse first thing in the morning.

"A lot of time in the winter months, you have the heater going, so you're breathing dry air all night. Use a humidifier in your room at night when you're sleeping," Kathleen Tibbetts, MD, assistant professor of otolaryngology at the University of Texas Southwestern Medical Center, told Health. You can also heat a pot of water and inhale the soothing steam.

Environmental Pollutants

Industrial emissions and smoke can cause inflammation and irritation of the tissues that line the throat, causing a sore throat. Environmental pollutants can also weaken the immune system. Decreased immunity can make it easier to contract viral infections that cause a sore throat.

Muscle Strain

Some evidence suggests that aerobics instructors and teachers have more frequent sore throats. Yelling and screaming can hurt your throat, but so can talking.

Recent Intubation or Surgery

Intubation is a procedure in which a healthcare provider inserts a tube into the throat to help you breathe. This procedure, as well as surgeries that affect the throat area, can cause discomfort. You may also experience a dry throat, coughing, and muscle strain after surgery.

Smoking 

Smoking releases chemicals that cause inflammation and irritation of the tissue that lines the throat. It can weaken the immune system, making you more susceptible to viral infections that cause a sore throat. Smoking is also a risk factor for GERD, which is a common cause of a sore throat.

Weak Immune System

A weak immune system makes it easier for bacteria and viruses to enter the body and harder for the body to fight them off. These germs are responsible for several infections that cause a sore throat.

A Quick Review

A viral infection, such as a cold or the flu, causes most sore throats. You might have a sore throat for several other reasons, such as allergies, acid reflux, strep throat, or, rarely, throat cancer.

Consult a healthcare provider if your symptoms don't improve within a few days or worsen. Less common causes of a sore throat, such as throat cancer, require treatment.