If you or your child has a sore throat caused by a virus or bacteria, it’s contagious. On the other hand, sore throats caused by allergies or other environmental factors aren’t contagious.

Viruses cause most sore throats, such as those that cause the common cold or flu. Approximately 85 to 95 percent of throat infections are viral.

Children ages 5 to 15 have a higher percentage of bacterial infections than younger children or adults. An estimated 30 percent of sore throats in this age group are bacterial.

Most sore throats typically get better in 7 to 10 days without treatment. However, sore throats caused by bacteria, such as strep throat, often need antibiotic treatment.

Read on to find out what types of sore throats are contagious, how long you may be contagious for, and what precautions you should take.

The common cold or flu are responsible for most sore throats, but there are many other possible causes.

It’s worth noting that you can have a sore throat due to an environmental cause alongside a viral or bacterial cause.

Contagious causesNoncontagious causes
viruses (such as the common cold or flu)allergies
bacteria (such as strep or pneumonia)postnasal drip
fungal infectionsdry or cold air
parasitessnoring or breathing with an open mouth
indoor/outdoor air pollution (smoke or chemical irritants)
gastroesophageal reflux disease (GERD)
neck or throat injury
vocal cord strain
intubation of the trachea
certain medications
thyroid disease
Kawasaki disease or tumor (rare)

Sore throats that are contagious

Sore throats caused by viruses

Viruses are the most common infectious cause of a sore throat. These include:

Sore throats caused by bacteria

Bacterial causes of sore throat include:

Tonsillitis

Tonsillitis, an inflammation of your tonsils, may be caused by a bacterium (usually strep) or a virus.

Other sore throat causes

Other causes of contagious sore throats include:

  • fungal infections of the throat, also called esophageal thrush, usually Candida albicans
  • parasites such as roundworms (ascariasis), which are rare in the United States

Sore throats that aren’t contagious

You can also have a sore throat that isn’t contagious. These may be caused by:

CausesContagious for how long
virus (such as mononucleosis, measles,whooping cough, croup)until symptoms are gone or even longer, depending on the particular virus
common coldfrom a couple of days before you notice symptoms until 2 weeks after
flufrom 1 day before symptoms start until 5 to 7 days after
chickenpox2 days before spots appear until the spots have all crusted over (usually in about 5 days)
tonsillitisuntil after the first 24 hours on an antibiotic
hand, foot, and mouth diseasegenerally 1 to 3 weeks, with the first week being the most contagious
strepuntil 24 hours after you’ve taken antibiotics (may take 2 to 5 days for symptoms to develop, and you’re contagious during that time)

Viruses

If your or your child’s sore throat is caused by a virus, you’ll be contagious until your symptoms are gone or even longer, depending on the particular virus.

Viruses can remain contagious on your hands, on surfaces, in bodily fluids, on clothing, and in droplets in air. You can minimize the spread of the virus by practicing good hygiene.

In general, if your child has no fever they can go back to school and participate in their regular activities.

Common cold

If you or your child has a sore throat from the common cold, you’ll be infectious from a couple of days before you notice symptoms until 2 weeks afterward.

You’re most likely to spread the virus in the first 2 or 3 days.

Flu

With the flu, you’re infectious from the time when the symptoms start until 5 to 7 days afterward.

Chickenpox

You or your child is infectious 2 days before chickenpox spots appear until the spots have crusted over. This usually takes about 4 to 5 days, though it can take longer.

Tonsillitis

The bacteria or virus that causes tonsillitis is contagious. If the cause is strep, you’ll be contagious until after the first 24 hours on an antibiotic.

Hand, foot, and mouth disease

If your child has hand, foot, and mouth disease, they’re most contagious during the first week of symptoms. But they may be contagious via the nose, mouth, and lungs for 1 to 3 weeks after that.

Their stool may be contagious for weeks to months.

Strep

Strep spreads through you or your child’s saliva and mucus. It’s contagious until 24 hours after you’ve taken antibiotics.

It’s important to continue the antibiotics for the full course of treatment prescribed. Strep can develop serious complications with other organs if not treated with antibiotics.

It may take 2 to 5 days for symptoms to develop and you’re contagious during that time.

Most sore throats in babies are caused by common viruses, such as a cold. Babies rarely have strep throat. If strep bacteria are present, infants usually don’t need antibiotic treatment.

According to the American Academy of Pediatrics, in most cases, the baby will be better in a few days.

If you or another family member has a viral or bacterial infection, it can be passed on to a child or baby via contact. Good hygiene practices are essential to prevent passing on an infection.

Viral and bacterial infections are easily spread, so it’s important for you and your family to take precautions, especially if someone is sick.

Here are some of the essential practices:

  • Wash hands often and thoroughly with soap and water. Rub them together for 15 to 30 seconds.
  • Use an alcohol-based hand sanitizer if soap and water aren’t available.
  • Sneeze or cough into the crook of your arm, rather than your hand.
  • If you or your child sneezes or coughs into a tissue, put used tissues into a paper bag for disposal.
  • Don’t eat from the same plate or share glasses, cups, or utensils.
  • Don’t share towels.
  • Use a new tooth brush after sore throat symptoms have cleared.
  • Clean toys and pacifiers often.
  • Wash clothing and bedding of the sick person in hot water.
  • Use disinfecting wipes to clean phones, remote controls, keyboards, door knobs, light switches, faucets, and other kinds of household items that are frequently touched.
  • Avoid public places if your baby or child is sick. Avoid contact with others who have sore throat or cold symptoms.
  • Keep up to date with your children’s vaccinations.

Most sore throats clear up on their own in a few days. But there are simple remedies you can use to make your throat feel better.

Try these home remedies to soothe a sore throat:

  • Stay hydrated.
  • Gargle with 8 ounces of warm water mixed with 1/2 teaspoon of salt. For children over 8 years old, use 1/4 teaspoon of salt.
  • Drink warm fluids, such as soup or tea. Try tea with honey, which is soothing for the throat. Chamomile tea can also soothe your throat.
  • Try inhaling steam from chamomile tea.
  • Use a humidifier if the air is dry.
  • Suck on an ice cube, hard candy, or lozenge. (But don’t give children under 5 anything they might choke on.)
  • Give your child cold or soft foods, like ice cream, pudding, or milkshakes.

If sore throat pain persists, or if you have a fever, you can try over-the-counter medications. These include:

  • acetaminophen (Tylenol)
  • ibuprofen (Advil, Motrin)
  • aspirin (but don’t give to a child if they have a fever)

You may also try to relieve sore throat pain with throat lozenges or an antiseptic throat spray.

Don’t give aspirin to a child for a fever

Note that children shouldn’t take aspirin if they have a fever. Give them children’s acetaminophen for a fever, instead.

In general, see a doctor if your or your child’s sore throat persists for more than 4 days.

Other symptoms along with a sore throat that require a doctor’s visit include:

  • fever that lasts more than 3 days or reaches 104°F (40°C)
  • fever above 102°F that lasts more than 2 days after taking an antibiotic
  • sore throat with a cold that lasts more than 5 days
  • rash or diarrhea after taking antibiotics
  • earache or drainage
  • headache
  • drooling
  • fever that returns after going away
  • blood in saliva
  • joint pain
  • swelling of the neck
  • throat hoarseness that doesn’t go away

Emergency conditions

Seek emergency treatment if your child has a sore throat and:

  • can’t swallow fluids or saliva
  • has severe trouble breathing
  • has a stiff neck
  • gets worse

Most sore throats are caused by common viruses. They heal on their own in a few days.

Sore throats caused by viruses and bacteria are contagious. The germs can remain on your hands, surfaces, and in the air sometimes for hours or days, depending on the particular virus or bacterium.

Sore throats caused by an allergy or other environmental factor aren’t contagious.

See a doctor if you or your child has a fever and other sore throat symptoms. If you’re prescribed antibiotics for strep throat, it’s important to take all of the medication prescribed. Strep can cause serious complications in children if it infects the brain or other organs.

Good hygiene practices can cut down on transmission and prevent future infection.