Keith's "clot" was a deep vein thrombosis...you can't "see" it on the outside. The leg was hot, red, swollen, the pain would start in the muscle at the top of the calf, but hurt and was swollen from the ankle to the thigh by the end. He'd knock the pain down with ibuprofen. He got short of breath when the clots hit his lungs, but still didn't know what was happening. The leg pain continued to increase. He'd call the doc and the office staff would tell him to take more pain meds and that it was just the knee injury. Janelle's description of what happens is excellent...the clot becomes encased.