What is the main symptom of bell palsy?

The primary symptom of Bell's palsy is facial droop, which occurs due to the sudden, unilateral weakness or paralysis of the muscles on one side of the face. This typically results from inflammation of the facial nerve (cranial nerve VII), impairing the ability to control facial expressions. Patients often experience a noticeable drooping of the mouth, eyelid, and other parts of the affected side of the face, leading to challenges in smiling, frowning, or closing the eye.

While loss of vision, difficulties in speech, and impaired hearing may occur with other neurological conditions or disorders affecting different cranial nerves, they are not characteristic symptoms of Bell's palsy. The condition primarily affects facial muscle control, making facial droop the most prominent and defining sign of this specific nerve dysfunction.