CRJ700 FLT CREW HAS LOSS OF PRESSURIZATION; DECLARES EMER AND DIVERTS.

Narrative

ENRTE AT OR ABOUT FL380; MY EARS POPPED AND I LOOKED AT THE PRESSURIZATION ON THE EICAS TO NOTICE THE CABIN ALT RAPIDLY INCREASING. REQUESTED LOWER ALT FROM CTR AND WERE CLRED TO FL180 WITH 10000 FT ON REQUEST. AS ACFT DSNDED; CABIN ALT CAUTION MESSAGE DISPLAYED AND QRH CONSULTED. PRIOR TO FINISHING QRH FOR CABIN ALT CAUTION MESSAGE; CABIN ALT WARNING MESSAGE DISPLAYED. IMMEDIATE ACTION ITEMS WERE COMPLETED AND QRH CHKLIST INITIATED FOR CABIN ALT WARNING MESSAGE. AS CHKLIST WAS BEING COMPLETED; FLT ATTENDANT CALLED THE COCKPIT AND WERE INFORMED ON THE SITUATION. THEY TOLD US THEY HAD SOME PAX HAVING HEALTH PROBS. EMER WAS DECLARED AND DIVERTED TO ZZZ. QRH COMPLETED FOR CABIN ALT WARNING MESSAGE. DISPATCH CONTACTED AND INFORMED. ALSO WHILE DSNDING; THE AUTOPLT OVERSPED THE ACFT 10-15 KTS INTO THE BARBER POLE. TOTAL TIME FROM BEGINNING TO TOUCHDOWN WAS ABOUT 20-25 MINS. SUPPLEMENTAL INFO FROM ACN 712516: IT WAS BROUGHT TO MY ATTN THAT A PAX HAD A LOSS OF BLOOD PRESSURE AND THAT SHE WAS ATTENDING TO.