Have a sore throat on one side? Learn 7 common causes, simple home fixes, and signs it’s time to call a doctor.
Quick answer: A sore throat on one side is often caused by a swollen lymph node, tonsillitis, or a canker sore. It can also come from an ear infection, a tooth problem, or mucus dripping down your throat. Most causes are mild and clear up on their own. But if you have trouble breathing or swallowing, see a doctor right away.
Most sore throats hurt on both sides. So when only one side hurts, it can feel strange. You might wonder if something is really wrong.
The good news is a sore throat on one side is usually not a big deal. Your throat has parts on each side, like tonsils and lymph nodes. These parts can get irritated one at a time. That is often why you feel pain in just one spot.
This guide walks you through seven common reasons for a one-sided sore throat. You’ll also learn simple ways to feel better at home. And we’ll cover the warning signs that mean you should call a doctor.
Why Does Your Throat Hurt on Just One Side?
Your throat is not one single piece. It has two tonsils, one on each side. It has lymph nodes on both sides of your neck too.
Lymph nodes are small, round parts that help fight germs. When germs attack one side more than the other, that side can swell up and hurt.
This is why a sore throat on one side is so common. One tonsil can get infected while the other stays fine. One lymph node can swell while its twin on the other side does not.
If you feel pain in left side throat when swallowing, it likely means something on that side is irritated or swollen. The same is true if the right side hurts instead. Your body is simply reacting to one spot more than the other.
7 Common Causes of a Sore Throat on One Side
Here are the seven most common reasons people feel a sore throat on one side.
1. Swollen Lymph Nodes
Lymph nodes sit on both sides of your neck. They swell up when your body fights an infection nearby.
If a germ is attacking the left side of your neck more, that lymph node may swell more. This can cause a sore throat on one side, often felt as a tender lump.
The swelling usually goes down once the infection clears. This can take a few days to two weeks.
See a doctor if the swelling lasts more than two weeks. Also call if you have a fever that won’t go away, or if you lose weight without trying.
2. Tonsillitis
Tonsillitis means your tonsils are swollen and sore. You have one tonsil on each side of the back of your throat.
Sometimes both tonsils swell the same amount. But often, one swells more than the other. This can make one side of throat hurts more than the other.
Signs of tonsillitis include:
- A fever
- Bad breath
- Trouble swallowing
- Red tonsils with white or yellow spots
- Swollen neck glands
Most viral tonsillitis clears up in three to four days on its own. If a bacterial infection is causing it, a doctor may give you antibiotics for up to ten days.
3. Peritonsillar Abscess
This one needs quick attention. A peritonsillar abscess is a pocket of pus that forms next to a tonsil.
It often starts as tonsillitis that gets worse. The pain is usually much stronger on one side than the other.
Watch for these signs:
- Trouble opening your mouth all the way
- A muffled voice, like you’re talking with a hot potato in your mouth
- Drooling because swallowing hurts too much
- Ear pain on the same side
- A high fever
If you notice these signs, see a doctor the same day. A peritonsillar abscess usually needs to be drained by a medical professional.
4. Canker Sores
A canker sore is a small, painful spot inside your mouth. It can form on your cheek, tongue, or near the back of your throat.
When a canker sore shows up near the back corner of your mouth, it can cause a painful throat on one side when swallowing. The sore itself is small, but it can sting a lot.
Most canker sores heal within two weeks without any treatment. You can ease the sting with a cold drink or an over-the-counter gel made for mouth sores.
5. Ear Infections
Your ear and throat are connected by a small tube called the eustachian tube. This tube runs from your middle ear down to the back of your throat.
When one ear gets infected, pain can travel down this tube. This is called referred pain, and it can feel like a sore throat on one side.
Other signs of an ear infection include:
- Ear pain or a feeling of fullness
- Trouble hearing clearly
- Mild fever
- Fluid draining from the ear
If ear pain comes with throat pain, tell your doctor about both. This helps them find the real cause faster.
6. Tooth or Dental Infections
A bad tooth can cause more than just tooth pain. An infected tooth, especially a back molar or wisdom tooth, can send pain down into your jaw and throat.
This often causes pain on just one side, matching the side of the bad tooth. You may also notice:
- Pain when chewing
- Sensitivity to hot or cold food
- Swelling in your cheek or jaw
- Swollen lymph nodes under your jaw
A dentist can check for this with an exam or an X-ray. Treating the tooth usually clears up the throat pain too.
Learn More: How to Stop Tooth Pain Fast: 10 Proven Relief Methods
7. Postnasal Drip
Postnasal drip happens when extra mucus drips down the back of your throat. Your nose makes mucus every day, but colds and allergies make it worse.
If you sleep on your side, mucus can pool on that side of your throat overnight. This often leads to a sore throat on one side that feels worse in the morning.
You may also notice:
- A cough, especially at night
- A scratchy feeling in your throat
- The need to clear your throat often
Postnasal drip usually gets better once the cold or allergy season passes. A decongestant can help in the meantime.
Home Remedies to Soothe a One-Sided Sore Throat
Most causes of a sore throat on one side can be eased at home. Try these simple steps:
- Gargle warm salt water. Mix a half teaspoon of salt into a warm glass of water. Gargle a few times a day to ease swelling.
- Take an OTC pain reliever. Ibuprofen or acetaminophen can lower pain and swelling. Follow the directions on the label.
- Drink warm liquids. Tea with honey or warm broth can soothe irritation as it goes down.
- Use a humidifier. Moist air can stop your throat from drying out at night.
- Suck on a lozenge. This keeps saliva flowing, which naturally soothes your throat.
These steps often help with mild causes like postnasal drip or early tonsillitis. They won’t fix a tooth infection or a peritonsillar abscess, though. Those need a doctor’s care.
When to See a Doctor
Many cases of a sore throat on one side get better without medical care. But some signs mean you need help right away.
Call a doctor or go to urgent care if you have:
- Trouble breathing
- Trouble swallowing your own spit
- A muffled or strained voice
- A fever above 101°F that won’t go down
- Pain that lasts more than a week
- Swelling that keeps growing
- A rash along with your sore throat
These signs can point to an infection that needs antibiotics or draining. It’s always better to get checked than to wait too long.
The Bottom Line
A sore throat on one side is usually caused by something simple, like a swollen lymph node or a canker sore. Your throat has matching parts on each side, so it’s normal for only one to act up.
Pay attention to any extra signs, like ear pain, tooth pain, or trouble swallowing. These clues can help you and your doctor figure out the real cause faster.
If home remedies aren’t helping after a few days, or if you notice any warning signs, don’t wait it out. A quick visit to the doctor can bring relief and peace of mind.
Frequently Asked Questions
Is it normal to have a sore throat on only one side?
Yes, it’s common. Your tonsils and lymph nodes come in pairs, so one side can swell more than the other.
Can a sore throat on one side be strep throat?
Yes. Strep throat can affect both sides equally, or feel stronger on one side. A doctor can test for strep with a quick throat swab.
Why does the left side of my throat hurt more when I swallow?
Pain when swallowing on one side often points to a swollen tonsil, a canker sore, or a swollen lymph node on that side. A tooth infection can also cause this.
How long does a one-sided sore throat usually last?
It depends on the cause. A viral sore throat often clears in three to five days. A canker sore can take up to two weeks to heal fully.
Should I worry if my sore throat on one side comes with ear pain?
Ear pain with throat pain often points to an ear infection, since the two areas connect through a small tube. It’s worth mentioning both symptoms to your doctor.
