Shooting the calf blue lumps may be physical factors, may also be the coagulation mechanism factors, or allergic factors, etc., it is recommended to consult a doctor in a timely manner, consult the relevant professionals, symptomatic treatment. 1. Physical factors: a sudden violent blow, subcutaneous capillary rupture, local oozing and produce bruises, manifested as green lumps, a short period of time need to be cold compresses, followed by warm water bags or hot towels, generally about a week, this phenomenon will disappear on its own. 2. Coagulation mechanism factors: reduced vascular elasticity, thrombocytopenia or lack of coagulation factors and other issues may lead to bruises after patting the calf. It is recommended to go to the regular hospital to find out the cause and deal with it in time. 3. Allergic factors: for example, artificial urticaria patients with increased reaction to external mechanical stimuli, after patting may cause blue lumps.