Sharp pain in heel today. foot would come up from floor at times when it was sharp. pain not constant. what could it be?

Evaluation possibly.: There are various conditions that can account for your symptoms. Since the pain is not constant and appears to be only when the heel is in contact with the floor, it may be that you have picked up a foreign body. Depending on the heel placement, the heel my hurt or not. Another reason could be that you are in the beginning stage of developing plantar fasciitis or a type of heel spur problem.

WearAHeelPadForNow: After you pull-out that rusty nail, tell me if it doesn't feel better. No? OK. Then maybe it's what's called a "heel spur." No, not the ones cowboys wear on their boots but a little extension of bone off the heel bone. They can cause pain. If the pain is further up the heel, it could be a tendon irritation. Or further down, some fascia acting up. In any case, you'll need a doctor to diagnose it.