Capillary bleeding on the skin of the lower extremities may be caused by skin diseases such as cutaneous vasculitis, allergic purpura in allergy-prone people, or senile purpura in the elderly. Capillary bleeding on the heel of the foot may be caused by black heel disease caused by friction between the heel of the foot and the shoe during exercise. An overdose of heparin or warfarin can also cause capillary bleeding in the lower limbs.