I have been having these random attacks of pain in the backs of my thighs. It feels like the pain of getting blood drawn only much worse. It kind of starts like a cramp then turns to excruciating burning pain. There are no visible signs before or after. It lasts a few minutes, and I get some relief from ice, and keeping my leg straight. I am 68, and have a type of leukemia (CLL). I get regular check ups with blood work, and so far am in the watch and wait phase. I have no warning when this happens. Sometimes it wakes me up, and I just ride it out. Bending my leg makes it hurt worse. Any suggestions would be appreciated. Thank you, Sally Sloan