Possible causes of facial numbness include peripheral neuropathy, shingles and transient ischemic attack, says Mayo Clinic. In general, numbness is the first outward sign of nerve malfunction. Less commonly, facial numbness is symptomatic of a problem with the central nervous system. On its own, facial numbness typically isn't associated with any life-threatening diseases.
Peripheral neuropathy is a nerve dysfunction with a variety of known causes, according to Mayo Clinic. These include injuries, toxic exposure and diabetes mellitus. Irregular levels of potassium and calcium can set the conditions for neuropathy, says The Neuropathy Journal.
Caused by a viral infection, shingles-related numbness can affect people before painful blisters appear, reports Brown University. However, the back and the upper torso are the most common sites for shingles-related tingling. Shingles symptoms usually go away in two to three weeks, but lingering effects can last for months.
When facial numbness is associated with a migraine, the numbness typically occurs during the early phases of migraine onset, according to WebMD. A kind of miniature stroke, transient ischemic attack causes facial numbness when blood flow to a particular brain region in interrupted. Transient ischemic attack is a temporary disorder, but it is often a warning sign of an full-blown stroke in the making.