Why at night especially do my shins & calfs get sharp shooting pains, also fron the knee down on both legs swell up. especially my feet & ankles & stay that way for days ?

Two problems: You have swelling, and shooting pains to the lower legs. I would make sure you are not pregnant, don't have varicose veins, are not flat footed (if so wear arch supports), if on any medications - check side effects, type of shoes you've been wearing? The shooting is usually nerve related but the swelling can be causing pressure on the nerves. If persists see a oc.

Neuropathy/vascular: Shooting pains can be a form of neuropathy or condition affecting peripheral nerves. Swelling could be related to venous circulation in legs where valves in veins are not functioning correctly and consequently fluid accumulates in feet and legs. See a physician for a complete examination. Other systemic causes are possible.