Jaundice hospital stay and now high blood pressure

What a week, a normal newborn rash landed us at the drs wednsday afternoon, dr notice he looked pretty yellow. Did stat bloodwork for bill level,direct coombs, and blood type. Came back at 18 told to head to the hospital they have a room waiting for him,by Thursday night it was down to 12, but in came a new issue.. Sudden high blood pressure.. So he got a kidney u/s, chest x-ray and urinealysis. Everything came back fine. They finally let us go Friday afternoon after realizing the dr he was gonna see for a consult was at a different kaiser.  He got set up with a check up for Monday, he has his 2-3wk well check set for Friday, he has a appt with the Nephrotologist set for 11/25. So we have no clue why he’s having high blood pressure, they were all done while he was resting/ sleeping so they shouldn’t had been high.