Hi. How long the child is putting pressure to pass urine? From his birth or recently. Normally babies do apply some pressure or cry while passing urine. But applying too much pressure is not normal. If it is recently that he is applying pressure, then it is not normal. We need to see if he has got any infection. How is the urine steam? Is he having good stream (urine going some distance like an Arch before falling down) or falling near him vertically. If there is some obstruction to pass urine it will not  travel some distance before falling down. Pls observe how he is passing urine without a diaper. Also how frequently he is passing urine? How is his weight gain?