What causes a high eosinopli count,border line low rbc,rest of cbc in normal.u&e kidney fucnt which shows low potassium and creatinin. no liver test?

No one can answer: I'm a lab specialist. Questions like this simply cannot be answered. You haven't told us how high the eos are, how low the potassium is. Low creatinine means nothing but is unusual in a young man unless he's malnourished. Lab reference ranges are set so that several percent of healthy folks fall outside. If you feel well, stop worrying.