I use catheters every time I urinate and have been doing so for over one year. I am a 67 year old, active male, and the reason for the catheter use was eurogynic bladder nerve gone or something like that. I have not had any trouble or UTI s since having to use catheters. Tonight, for the first time, it felt like the last few inches of the catheter went in unusually hard, but my bladder was quite full. At the end of the urine drain through the catheter, I passed one small drop of blood. Is this anything to worry about if it does not continue the next time I urinate, or is this a genuine cause for serious concern? Thanks.