According to the Mayo Clinic, deep vein thrombosis is a blood clot that forms in one of the deep veins of the body, usually in the legs. It often causes pain, swelling or warmth in the leg. DVT can also occur without noticeable symptoms.

Milwaukee Bucks guard Damian Lillard will likely be sidelined indefinitely, as the team announced Tuesday he has deep vein thrombosis in his calf.