Stroke symptoms. If this has occurred suddenly and includes the whole half of your body (face, arm, +/- leg), it may be a sign of a stroke. You should go to an emergency room for a complete evaluation. Complicated migraines and some spine problems can also cause hemi-body or extremity numbness, but you should have a complete evaluation to distinguish among these possibilities.
Stroke is likely. If that occurs at any time, anywhere, immediate emergency room evaluation should be done and the person should get there by ambulance. The earlier the intervention the better the result.
Numb in body. There are many conditions that can cause this symptom. Stroke or what we call brain infarction. A brain infarction is when the brain is prevented from receiving blood, leading to tissue damage, stroke, and possible fatality. However there are conditions that often can cause numbness. A conversion reaction or conversion disorder is characterized by the loss of a bodily function that is involuntary.