Palin did not disclose an exact diagnosis for her condition, though she noted that she underwent a CT scan, numerous tests and was prescribed steroids and other medications. She said her doctors speculated she may have a case of Bell's palsy, a type of temporary facial paralysis, induced by "stress or lack of sleep."

According to John Hopkins Medicine, Bell's palsy is "an unexplained episode of facial muscle weakness or paralysis. It begins suddenly and can get worse over 48 hours. This condition results from damage to the facial nerve (the 7th cranial nerve). Pain and discomfort usually occur on one side of the face or head."