Why did one side of my face suddenly become numb?

Facial numbness on one side is a common symptom that may be caused by various factors: 1. Exposure to cold: Numbness may occur due to cold wind or cold water stimulation on one side of the face, leading to microvascular circulation disturbance, muscle spasm, and numbness. 2. Emotional excitement: During emotional excitement or anxiety, the body releases stress hormones such as adrenaline, which may cause vasoconstriction and elevated blood pressure, thereby affecting the function of facial nerves and causing numbness on one side of the face. 4. Facial nerve inflammation: Also known as Bell's palsy, this is an acute facial nerve dysfunction often presenting with facial muscle weakness and numbness. 5. Hypertension: Poorly controlled blood pressure may lead to excessive dilation of cerebral blood vessels, compressing local nerves in the brain and causing facial numbness. 6. Other neurological diseases: Conditions such as stroke, cerebral infarction, trigeminal neuralgia, and facial nerve paralysis may also lead to numbness on one side of the face. 7. Allergy: Using cosmetics containing allergens or contact with allergens on one side of the face may also cause facial numbness. If you have any concerns, it is recommended to seek medical attention promptly.