A 48-year-old man from Sudbury has appeared in court to admit making a threat to kill.
Robert Underwood, of Beatty Road, also pleaded guilty to a charge of being in possession of an offensive weapon.
Underwood was arrested following an incident on a bridge over Springlands Way in Sudbury on the afternoon of May 25. It is thought he had tried to throw himself off the bridge.
Afterwards, Underwood was taken to West Suffolk Hospital in Bury St Edmunds for treatment to cuts to his arms.
At Ipswich Crown Court on Tuesday, Judge David Goodin told Underwood that he would continue to be remanded in custody until he is sentenced next month.