What Could Cause Hematuria?

A few days back, my father mentioned that he got a small amount of blood in urine. We consulted a doctor who advised us to get an ultrasound, urine culture and urinalysis done. As per the ultrasound report, he has a 42mm diameter cortical cyst at the lower pole, 38mm diameter at the upper pole of his left kidney. Also, there is another cortical cyst at upper pole of his right kidney (23mm diameter). We are worried that these seem pretty large cysts and wish to know what we can do to a) treat these cysts b) prevent more from forming. Kindly advise.