I woke up at night when i steped out of bed my legs were dead i fell on the floor after a few minutes the feeling came back what was it?

Dead legs: There are several possibilities, all potentially rather serious, ranging from a threatened brain stem stroke to a problem in the spinal cord in the neck, to blood vessel problems in the legs. I urge you to see your family doctor or emergency room quickly. Those symptoms should not be ignored. They should be evaluated carefully urgently.

This could be TIA. : Some possible causes are tia-transient ischemic attack, if not treated could cause stroke. Other possibilities are poor transient circulatory problem in legs or spinal cord, , some rare type seizure, etc. You need to be investigated in detail.