If over 50 is very bothersome. Young men often get to the high 40s due to their level of testerone-but, shouldn't be over 50. A red cell mass should be done in nuclear medicine to see his actual red cell mass-this is the first step in diagnosing his problem. One would be suspicious of someone who has taken steroids that they are taking they again and causing the problem. Probably nothing unless your count is a hematocrit much above 48 or so.
High counts can cause strokes, etc., and can be a marker for polycythemia vera.
However, this is always above a Hct of 50. Re-check it in 3 weeks, but I'd keep a close eye on this. Are the white cells lymphocytes, neutrophils, etc. These are all important questions. Viral syndromes are notorious for causing low white blood cell counts.