The bruising at the big fish margin of the left hand may be physiologic, and it may be related to pathological factors such as venous reflux disorders caused by multiple factors and other diseases. 1. Physiological factors: the skin of the left hand at the big fishbone is thinner and fairer, and the number of subcutaneous veins passing through here is abundant, which can show the symptom of bruises at the big fishbone. 2. Pathological factors: such as deep vein valve insufficiency, deep vein thrombosis, head and arm vein stenosis, etc. can cause venous blood reflux obstruction, superficial vein dilation, coupled with the abundance of local veins in the pisiform region, it is easy to appear the symptoms of blue veins. If the left palm of the big fish appeared bruises, it is recommended to go to the hospital in time to find out the cause, if it is a pathological factor, plus the active treatment, so as not to delay the condition.