Former Cambridge City Councilor Nadeem A. Mazen announced Sunday he has dropped out of the crowded race for the Democratic nomination to succeed US Representative Niki Tsongas.

Mazen, who grew up in Andover, said he ended his campaign because his fund-raising hasn't kept pace with several of his opponents. And, he told the Globe, a health scare late last year — a pulmonary embolism — also set him back.

"I was surprised by the momentum and the speed with which others have raised nearly or over a million dollars," Mazen said. "I can't compete with fundraising like that."

Read the complete original version of this item...