lump on leg

Saturday I had a lump come up on the back of my thigh, size of a silver dollar, raised up 1/4 inch...over Saturday and Sunday it went away but now I have a huge, horrible bruise..what is it?

[Dr. Kokil Mathur]

Hi!
One possibility is that you have injured yourself like from the edge of a chair.
If you are not on any medications like anticoagulants, blood thinners or birth control pills then this could be due to clotting disorders, low platelet count, fragile spider veins, deep vein thrombus, deficiency of Vitamin B12, folic acid, or Vit K, a liver disease or certain cancers. It could also be due to pressure urticaria. If you are on medications then you need to discuss that with your doctor.  Take care!