When swallowing causes pain specifically on the right side of the throat, the experience is medically termed unilateral odynophagia. The discomfort signals inflammation, irritation, or structural changes affecting the tissues or nerves on that side of the neck and throat. While a sore throat is common, pain focused on one side can point toward a variety of causes, ranging from highly localized infections to issues originating elsewhere in the head or neck.
Common Infectious and Inflammatory Causes
Tonsillitis, an infection of the lymphoid tissue known as the tonsils, typically affects both sides, but the inflammation and resulting pain can be significantly worse in the right tonsil. This asymmetrical response can be due to a more aggressive localized infection or a minor anatomical difference in the tonsillar tissue itself.
In more severe cases, an infection may progress into a peritonsillar abscess, often called Quinsy, which is a collection of pus forming next to one of the tonsils. This condition is characterized by intense, rapidly worsening unilateral throat pain, often accompanied by a muffled “hot potato” voice and severe difficulty opening the mouth fully (trismus). Infectious Mononucleosis (Mono), caused by the Epstein-Barr virus, can also lead to dramatically enlarged and tender lymph nodes on one side of the neck, creating unilateral pain when swallowing due to mechanical pressure.
Localized inflammation can arise from post-nasal drip, where mucus drainage irritates a specific area of the throat. If a person habitually sleeps on their right side, the irritating mucus may pool or drain more consistently along the right side of the pharynx, leading to localized inflammation and discomfort upon swallowing. Similarly, laryngitis or pharyngitis, while generally widespread, can cause inflammation that is unevenly distributed, making one side feel more painful or raw.
Irritants and Non-Infectious Structural Issues
Pain that occurs only on the right side when swallowing can frequently be traced to non-infectious causes involving physical or chemical irritation. Gastroesophageal Reflux Disease (GERD) or Laryngopharyngeal Reflux (LPR) involve stomach acid backing up into the esophagus and sometimes reaching the throat. This acid splash can cause unilateral irritation, especially if a person frequently sleeps on their right side, allowing the acid to settle and burn the right side of the throat tissues.
A localized mechanical injury can also produce a sharp, one-sided pain. This might occur after swallowing a piece of hard or sharp food, such as a crisp chip or a small fish bone, which can scratch or become temporarily lodged in the right side of the throat lining.
Swollen cervical lymph nodes, which function as filters for the body’s immune system, are a common non-infectious cause of unilateral pain. These nodes on the right side of the neck can swell in response to any infection or inflammation in the head, face, or throat area. The pressure from the enlarged node can be felt as pain when the surrounding structures move during swallowing. Dryness from environmental factors or breathing through the mouth while sleeping can also lead to an asymmetrical sore throat, as the right side may become more desiccated and irritated than the left.
Understanding Pain Referral
The sensation of pain in the throat does not always mean the source of the problem is in the throat itself. The phenomenon of referred pain occurs when nerve pathways overlap, causing the brain to misinterpret the signal’s origin. The glossopharyngeal nerve (Cranial Nerve IX) and the vagus nerve (Cranial Nerve X) connect the throat to other structures, including the ear and the jaw, making referred pain a common cause of unilateral odynophagia.
Ear pain, or otalgia, can be referred to the throat because the same nerves supply both areas. Therefore, a right ear infection or pressure change can be perceived as pain in the right side of the throat when swallowing. Similarly, issues with the jaw, such as Temporomandibular Joint (TMJ) dysfunction on the right side, can mimic throat pain.
Dental issues like a right-sided tooth abscess or an impacted molar can also refer pain to the neck and throat area. Subacute thyroiditis, an inflammation of the thyroid gland, can sometimes be the cause of unilateral pain. Inflammation localized to the right lobe can cause neck tenderness and pain that radiates to the jaw or ear, which is often felt most acutely during swallowing.
Immediate Warning Signs
Any difficulty with breathing, including noisy breathing (stridor), is a serious red flag that suggests potential airway obstruction and requires immediate emergency care. Similarly, the inability to swallow one’s own saliva, leading to excessive drooling, suggests severe inflammation or an obstruction.
Medical attention should be sought if the pain is accompanied by a high fever, generally above 101°F (38.3°C), that does not respond to over-the-counter medication. The inability to open the mouth fully, known as trismus, is a symptom often associated with a deep neck space infection like a peritonsillar abscess. Pain that persists for more than seven days without any sign of improvement warrants a consultation with a healthcare provider for a thorough examination and diagnosis.