hello,my left leg,the feet is swelling,

i did not injure or hurt myself

no pain,what could it be,am 27yrs,65kgs,not sure about my exact height but am not short,am like 1.5ft'

i have done a number of tests ECG,blood tests,a scan for the leg(cant remember how its called),the results were ok, i was just given a compression stocking,and told to ellevate my leg,the condition has been for three months