Sore Throat on One Side: Causes and What It Means

Why Does Your Throat Hurt on Just One Side?

A sore throat that affects only one side is more specific than a general sore throat and often points to a particular underlying cause. While a standard cold or flu typically causes symmetrical throat pain, one-sided throat pain can indicate localized infections, post nasal drip from one congested sinus, or conditions that affect structures on only one side of the throat.

In most cases, a one-sided sore throat is not serious and resolves on its own or with simple treatment. However, certain causes — like peritonsillar abscess — require medical attention. Understanding the possible causes helps you decide whether to treat at home or see a doctor.

Common Causes

1. Post Nasal Drip (One-Sided)

When mucus drains predominantly from one congested sinus or one side of the nasal passage, it can irritate the throat on that same side. This is especially common with a deviated septum or unilateral sinus congestion. The dripping mucus causes inflammation and a raw, sore sensation on the affected side, often worse in the morning after lying down all night.

Treatment involves addressing the nasal congestion causing the drip — sinus pressure relief techniques, saline irrigation, and nasal corticosteroid sprays can all help restore normal bilateral drainage.

2. Tonsillitis (Unilateral or Worse on One Side)

While tonsillitis usually affects both tonsils, it can be more severe on one side, creating asymmetric pain. Viral tonsillitis (the most common type) causes swollen, red tonsils with pain radiating to one ear on the worse side. Bacterial tonsillitis (strep throat) can also present with one-sided predominance.

Signs of tonsillitis: Swollen tonsils visible at the back of the throat, white or yellow patches on the tonsils, difficulty swallowing, swollen lymph nodes on the affected side, fever, and bad breath.

3. Peritonsillar Abscess

A peritonsillar abscess is a pocket of pus that forms next to one tonsil, usually as a complication of untreated or undertreated tonsillitis. It is the most common deep infection of the head and neck in adults and requires medical treatment.

Warning signs: Severe one-sided throat pain that worsens rapidly, difficulty opening the mouth (trismus), drooling because swallowing is too painful, a muffled or “hot potato” voice, swelling visible on one side of the throat, fever, and the uvula may be pushed to the opposite side.

This is a medical emergency. A peritonsillar abscess requires drainage by a doctor and antibiotics. Do not try to manage it at home.

4. Swollen Lymph Node

The cervical lymph nodes on one side of the neck can swell in response to a localized infection — a tooth infection, ear infection, or skin infection on that side of the face. The swollen node can cause referred pain to the throat on the same side. The node itself may be tender and palpable as a firm lump under the jaw or along the side of the neck.

5. Tooth Infection or Dental Issues

An infected or impacted wisdom tooth, particularly a lower one, can cause referred pain to the throat on the same side. Dental abscesses on the upper molars can also irritate the throat. If your one-sided sore throat coincides with tooth pain, jaw soreness, or gum swelling, a dental cause is likely.

6. Laryngitis or Vocal Cord Issues

Inflammation of the larynx (voice box) can sometimes produce one-sided pain, particularly if one vocal cord is more irritated than the other. This is often caused by acid reflux (laryngopharyngeal reflux), vocal strain, or infection. Hoarseness, voice changes, and a scratchy sensation accompany the pain.

7. Glossopharyngeal Neuralgia

This rare condition causes intense, stabbing pain on one side of the throat, tongue, ear, or tonsil area. The pain is nerve-based (not from infection) and occurs in sharp episodes lasting seconds to minutes, often triggered by swallowing, talking, coughing, or yawning. While uncommon, it is important to recognize because it requires specific neurological treatment.

8. Canker Sore (Aphthous Ulcer)

A canker sore on the back of the throat or on one tonsil can cause localized pain that feels like a one-sided sore throat. These small, painful ulcers are round or oval with a white or yellow center and red border. They typically heal within one to two weeks without treatment.

9. Throat Irritation From Sleeping Position

Sleeping with your mouth open on one side can cause localized dryness and irritation to the throat on the side facing upward. This is a common cause of morning-only one-sided sore throat that resolves after drinking fluids and resuming normal activities. Using a humidifier and addressing any nasal congestion that forces mouth-breathing often resolves this issue.

Home Remedies for One-Sided Sore Throat

Salt Water Gargle

Dissolve half a teaspoon of salt in eight ounces of warm water. When gargling, tilt your head slightly toward the affected side to direct the salt water to the painful area. Gargle for 30 seconds and spit. Repeat four to five times daily. Salt water reduces swelling and draws out irritants.

Warm Fluids

Warm herbal teas with honey, ginger, or chamomile soothe the irritated throat and provide anti-inflammatory benefits. Honey in particular coats the throat and has mild antimicrobial properties. Avoid very hot beverages that could further irritate inflamed tissue.

Over-the-Counter Pain Relief

Ibuprofen (Advil) is often the best choice because it reduces both pain and inflammation. Acetaminophen (Tylenol) is an alternative for those who cannot take NSAIDs. Throat lozenges with benzocaine or menthol provide temporary topical numbing. Throat sprays like Chloraseptic deliver localized anesthetic directly to the painful area.

Address Nasal Congestion

If post nasal drip is the cause, treating the nasal congestion resolves the sore throat. Saline nasal irrigation with a neti pot, nasal corticosteroid spray, and steam inhalation help clear the drainage causing throat irritation.

Humidify the Air

Dry air worsens throat irritation. Running a cool-mist humidifier in your bedroom, especially during winter, maintains moisture levels that keep the throat lining hydrated and less susceptible to irritation.

Rest Your Voice

If vocal strain or laryngitis contributes to the pain, minimize talking, avoid whispering (which actually strains the vocal cords more than soft speaking), and stay hydrated.

When to See a Doctor

Seek medical attention if you experience any of the following with a one-sided sore throat:

• Difficulty breathing or swallowing: May indicate significant swelling or abscess.
• Cannot open your mouth fully: Trismus is a hallmark of peritonsillar abscess.
• Drooling: Suggests swallowing is too painful, which can indicate a serious infection.
• High fever above 101 degrees Fahrenheit: Combined with one-sided pain, suggests bacterial infection.
• A visible lump or swelling on one side of the throat: Could be an abscess or enlarged tonsil.
• Symptoms lasting more than a week: Without improvement, further evaluation is warranted.
• Persistent hoarseness beyond two weeks: Should be evaluated to rule out vocal cord issues.
• Unexplained weight loss with persistent sore throat: Warrants further investigation.
• Ear pain on the same side: Referred pain from the throat to the ear often indicates tonsillitis or abscess.

A doctor can perform a throat examination, rapid strep test, or refer you to an ENT specialist for endoscopic evaluation if needed.

Bottom Line

A sore throat on one side is usually caused by post nasal drip, localized tonsil inflammation, a swollen lymph node, or dental issues — all of which are generally manageable with home care. Salt water gargles, warm fluids, pain relievers, and addressing any underlying nasal congestion are the most effective home treatments. However, severe one-sided throat pain with difficulty opening the mouth, drooling, high fever, or visible throat swelling requires prompt medical evaluation to rule out peritonsillar abscess, which needs professional drainage and antibiotics.