Facial Paralysis (Bell's Palsy)

It is the sudden paralysis of one half of the face, not originating from the brain, but as a result of the nerve that controls facial expressions becoming inflamed, swollen, and crushed (as it exits the bony canal behind the ear), thus failing to send electricity to the muscles.

The life-saving and most reassuring difference is this:
In Brain Hemorrhage/Stroke: The patient can close their eye and raise their eyebrow, ONLY the lower part of their mouth sags. This is accompanied by an inability to hold the arm/leg and speech impairment.
In Bell's Palsy (Facial Paralysis): The paralysis is only in the face (arms are intact). However, the ENTIRE face is paralyzed; the patient CANNOT close their eye, raise their eyebrow, or wrinkle their forehead.

Usually, 1-2 days before the paralysis starts, a mild pain is felt behind the ear (at the hole where the nerve exits).
When you wake up the next morning: One side of the face is stiff and numb. The mouth shifts/slants towards the healthy side. The patient cannot whistle, cannot show their teeth, and spills water from the side of their mouth while drinking. They cannot blink, and because the eyelid remains open, their eye burns severely (dries out).

Although the exact cause is not fully proven, the underlying main culprit is thought to be the Herpes Simplex (Cold Sore) Virus or previous viral upper respiratory tract infections.
Folk Belief (Being in a Draft): A cold wind does not directly cause paralysis, but sleeping in an air-conditioned environment or going out into the cold with wet hair constricts the capillaries in the face and is the biggest TRIGGER that sets the stage for the virus to invade the nerve at that moment.

The neurologist makes the diagnosis in 1 second just by looking at your facial expressions (asking you to squeeze your eye shut). Generally, an MRI or EMG is not needed in the first few days. An EMG is performed to see the nerve damage (death) only if the complaints have not improved at all despite 1 month passing, or an MRI is requested if a tumor/mass is suspected.

The Most Important Rule (First 72 Hours): If you go to the doctor within the first 3 days after the paralysis begins, the High-Dose CORTISONE (Prednol) pills prescribed by the doctor will instantly resolve the edema (swelling) in the nerve and prevent permanent damage/crookedness. Antiviral pills (Zovirax, etc.) are given alongside it.
Protecting the Eye: Because the patient cannot close their eye, the eye remains open while sleeping, dries out, and the cornea (transparent layer) can get scratched and lead to blindness. Therefore, the eye MUST BE FORCIBLY CLOSED FROM THE OUTSIDE WITH TAPE while sleeping, by applying artificial tear gel.
85% of patients return 100% to their former state (with zero trace) within 1 to 3 months (with physiotherapy and chewing gum/balloon blowing exercises).