you are correct. dark red or brown urine could be blood although there are medications and even certain foods that can change the color of the urine. this would have nothing to do with your recent hep b vaccine. one common cause of blood in the urine would be a urinary tract infection even if you are not feeling any other symptoms. just the way a nose can suddenly bleed the bladder can do the same. this would be high on my list if you were female. urinary tract infections are uncommon in men. a kidney stone can cause urinary bleeding as well. i would be advisable for you to see your medical provider today and have a urinalysis to see if you are indeed having a urinary tract bleed. if not your medical provider can search for other possibilities. two nights ago had dark red urine?
i am very concerned. i noticed today my urine if very dark and red or brown maybe blood. . the only recent change i have epericenced would be a hep b vaccine shot last week. i have no injuries. and this is a very sudden change.