Facial drooping is caused by Bell's palsy, a skull fracture or face injury, head tumors, stroke, and high blood pressure. It is also caused by diabetes, Lyme disease, autoimmune diseases and Ramsay-Hunt syndrome, according to Healthline.
Facial paralysis is a loss of facial movement that causes the muscles in the face to weaken or droop. Bell's Palsy is the most common cause of facial drooping, affecting 40,000 Americans annually, claims Healthline.
Drooping of the face normally occurs due to damaged or swollen facial nerves, or damage to the area of the brain that sends signals to the face muscles, according to MedlinePlus.