Deep Vein Thrombosis (DVT) Support Group
Deep-vein thrombosis, also known as deep-venous thrombosis or DVT, is the formation of a blood clot ("thrombus") in a deep vein. It can be caused by something preventing blood from circulating or clotting normally. Join the support group if you are coping with DVT and find others who are going through the same challenges.
I will note that the DVT itself can cause leg cramps, for sure. I had about four years where I couldn't stretch in bed without having my DVT leg immediately spasm into very painful leg cramps.
One other thing to think about also, but are you limping? If you're limping and getting more active, that can cause all sorts of ripple effects to the rest of your body. It might be enough to cause leg cramps and back spasms.
I agree with @rmb in regard to the hydration thing. I had to increase my liquid intake and my electrolytes for another medical issue and that's when my leg cramps (in my DVT leg) finally went away.