What may cause trace of blood in urine. I am 67 yrs.old, I am a very active person goes to gym 4 days a week plus on day 5 I may also do a 17 to 20 mile bike ride. My gym workouts consist of yoga, pliates, elipitical machine, body pump & some cardio but I don't run. I do take supplements, & I am on one med. for thyroid.
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