Bell's palsy is a neurological condition marked by sudden weakness or paralysis of the face muscles, typically affecting one side of the face.

This condition often emerges rapidly, sometimes within hours, and reaches its peak severity within 72 hours.

Rapid Onset of Face Weakness

The hallmark symptom of Bell's palsy is the abrupt onset of muscle weakness or paralysis on one side of the face. This weakness can range from a mild drooping to complete paralysis, inhibiting the ability to perform common face movements such as smiling, blinking, or wrinkling the forehead on the affected side.

The face creases and nasolabial fold typically disappear, and the corner of the mouth droops noticeably. A common observation is difficulty closing the eye, often resulting in the eye remaining partially open. This inability to close the eyelid fully deprives the eye of natural lubrication, increasing the risk of irritation.

Sensory Changes: Altered Taste and Sound Sensitivity

Beyond motor symptoms, Bell's palsy can affect sensory functions linked to the face nerve. Many patients report changes in taste, particularly a diminished or altered taste sensation on the anterior two-thirds of the tongue on the affected side.

Additionally, increased sensitivity to sound or hyperacusis may occur due to paralysis of the stapedius muscle—a small muscle in the middle ear controlled by the face nerve—that normally dampens loud noises. This heightened sensitivity can make everyday sounds seem unusually loud and uncomfortable.

Pain and Discomfort

Some individuals experience pain or discomfort around the ear either before or concurrent with the onset of face paralysis. This pain can be sharp or aching and is often described as occurring behind or around the ear area. Headaches and a sensation of numbness or heaviness on the affected side of the face are also reported, although true sensory loss (such as loss of touch or temperature sensation) is not typical since the face nerve is primarily motor.

Functional Difficulties

Bell's palsy affects several daily functions. Because muscle control over the lips and cheek is impaired, patients may find difficulty eating and drinking, with increased drooling due to loss of control over saliva. Speech may be slurred or less clear, complicating verbal communication. The affected nostril may also show decreased muscle tone, causing unintentional nasal airflow through the nostril. Some patients may experience involuntary face muscle spasms or twitches as muscles recover, a phenomenon called synkinesis.

Progression and Recovery

Symptoms usually develop rapidly over a few days, reaching maximum severity within one week. Without treatment, approximately 85% of patients begin to show partial recovery within three weeks, and many regain full function within three to six months. However, some may experience lingering weaknesses or complications, highlighting the importance of early assessment and intervention.

Dr. MH Hohman, in a 2024 medical authoritative source, states: "Bell palsy is the most common paralysis of the seventh cranial nerve, with an onset that is typically rapid."

Bell's palsy is a distinctive neurological disorder manifesting as sudden one-sided face muscle weakness or paralysis. Its hallmark symptoms include face droop, inability to close the eye, altered taste, and increased sound sensitivity. Accompanying pain and functional difficulties in eating and speaking are common. The condition progresses quickly but often improves with time. Accurate diagnosis led by awareness of its specific symptomatology is critical for effective management and coping.