DEEP VEIN THROMBOSIS (DVT) ...

What does a DVT, what does it feel like in the leg?

You can often feel the effects of a blood clot in the leg. Early symptoms of deep vein thrombosis include swelling and tightness in the leg. You may have a persistent, throbbing cramp-like feeling in the leg. You may also experience pain or tenderness when standing or walking but they may be no symptoms. 
Pain areas: in the calf, foot, or leg
Also common: swelling in extremities, tenderness, or warm skin.

This condition is serious because blood clots can loosen and lodge in the lungs.

Treatments include medication and use of compression stockings.