Thanks for writing to us.
I am really astonished that he has a large bruise
but Normal blood work-up. Either you can get a repeat INR (test for knowing the effect of warfarin
on blood) or there may be a concomitant therapy with aspirin
or aspirin like drugs, or he has some other reason for bleeding like vitamin C deficiency
or he is getting repeated injury
in the area of bruise (people may get bruises with injuries , even if they have INR in therapeutic range.).
Bad cold and cough are reasons enough for him to feel tired and lethargic.
You should consult your physician on both these issues at priority.
Best of luck