Unilateral tongue numbness can be an unsettling sensation. Medically termed paresthesia, this symptom describes an altered feeling such as tingling, prickling, or a complete absence of sensation. While often temporary and benign, it can sometimes signal underlying health issues that require medical attention.
Understanding the Causes
Causes of unilateral tongue numbness range from localized issues directly affecting the tongue to broader neurological or systemic conditions. Identifying the specific origin often depends on accompanying symptoms and recent events.
Local Causes
Dental procedures often cause temporary unilateral tongue numbness. Local anesthetics used during treatments like wisdom tooth extractions can directly affect nerves that supply sensation to the tongue, particularly the lingual nerve. Numbness typically resolves within a few hours as the anesthetic wears off, but in rare instances, nerve trauma from the injection or extraction process can lead to more prolonged numbness, sometimes lasting weeks or months. Trauma to the tongue itself, such as biting or burns from hot food or liquids, can also cause temporary numbness due to nerve irritation or minor damage.
Infections within the mouth, like an abscess, or inflammatory conditions can also irritate nerves, leading to localized numbness. Canker sores may cause tingling or burning sensations on the tongue before the sore becomes visible. Allergic reactions to certain foods or chemicals can manifest as tingling or numbness in the mouth and tongue, sometimes accompanied by swelling.
Neurological Causes
Unilateral tongue numbness can occur if there is compression or damage to the lingual nerve, which provides general sensation to the front two-thirds of the tongue on that side. Other cranial nerves, such as the hypoglossal nerve (responsible for tongue movement), can also be affected by injury or compression, potentially leading to both numbness and difficulty with tongue movement. Bell’s Palsy, a condition causing sudden weakness or paralysis of facial muscles on one side, can sometimes include sensory changes like tongue numbness due to its effect on the facial nerve.
More serious neurological events like a transient ischemic attack (TIA) or stroke can cause sudden unilateral tongue numbness. These conditions disrupt blood flow to the brain, affecting nerve function. When associated with a stroke, tongue numbness is typically accompanied by other sudden symptoms such as facial drooping, weakness on one side of the body, difficulty speaking, vision changes, or a severe headache. Multiple sclerosis (MS), an autoimmune disease affecting the brain and spinal cord, can also cause numbness or unusual sensations in the tongue due to nerve demyelination.
Systemic Conditions
Nutritional deficiencies, especially a lack of B vitamins like B12, can affect nerve health and function throughout the body, including the tongue. These deficiencies can cause neurological symptoms such as tingling or pins and needles. Low calcium levels, medically known as hypocalcemia, may also manifest as tingling around the mouth that can feel like tongue numbness. Conditions affecting blood supply, such as Raynaud’s phenomenon, where small arteries constrict, can temporarily reduce blood flow to the tongue, causing tingling or numbness.
When to Seek Medical Attention
Understanding when to seek medical attention for unilateral tongue numbness is important for ensuring proper care and identifying potentially serious conditions. The urgency of medical evaluation depends on the accompanying symptoms and the onset of numbness.
Emergency Signs
Immediate medical attention is necessary if unilateral tongue numbness appears suddenly, particularly when combined with other neurological symptoms. Call emergency services if the numbness is accompanied by:
Sudden weakness or paralysis on one side of the body
Facial drooping
Difficulty speaking or understanding speech
Vision changes
Sudden severe headache
Problems with balance or coordination
These symptoms can indicate a stroke or TIA, which are medical emergencies requiring prompt diagnosis and intervention.
Non-Emergency but Concerning Signs
Seek medical evaluation from a healthcare professional if the tongue numbness persists beyond a few hours or days, worsens over time, or recurs without a clear cause. It is also advisable to consult a doctor if the numbness is accompanied by pain, swelling, changes in taste, or if there is no obvious reason for the symptom, such as a recent dental procedure. If the numbness follows a dental procedure and lasts more than a day or two, or is accompanied by sharp pain or loss of taste, contacting your dentist for further evaluation is recommended. Persistent or unexplained numbness warrants professional diagnosis to rule out underlying conditions.
Diagnosis and Management Approaches
When experiencing unilateral tongue numbness, a medical professional will typically begin with a thorough evaluation to determine the underlying cause, including a detailed medical history and physical examination. The diagnostic process usually starts with gathering information about the onset, duration, and nature of the numbness, as well as any other symptoms experienced.
A physical examination will assess sensation, reflexes, and the function of cranial nerves, including those involved with the tongue and face. Depending on initial findings, further diagnostic tests may be ordered. These can include blood tests to check for nutritional deficiencies like vitamin B12 or imbalances in minerals such as calcium.
Imaging studies, such as MRI or CT scans, may be performed to visualize the brain and nerves, helping to identify neurological issues like stroke, tumors, or nerve compression. Nerve conduction studies can also evaluate nerve function.
Management of unilateral tongue numbness is entirely dependent on the specific cause identified. If the numbness is due to a local anesthetic from a dental procedure, it typically resolves on its own as the anesthetic wears off, though nerve trauma may require time for healing. For nutritional deficiencies, treatment involves addressing the deficiency, often through supplements. Neurological conditions, such as stroke or multiple sclerosis, require specific medical management tailored to the condition, which may involve medications or other therapies to manage symptoms and prevent progression. In some cases, such as with certain nerve compressions, surgical intervention might be considered. If the cause is benign or minor, the numbness may resolve spontaneously without extensive treatment.