Dorothy Crosbie, 83, was visited by a man on Monday who told her he had carried out more than £1,000 of work on her Stoke-on-Trent home.
Police said he searched her home then took her into town to withdraw money from her building society.
She later fell ill and is in hospital where her condition on Thursday was described as "poorly".
A spokesman for Staffordshire Police said: "This sort of crime is very traumatic and we believe her current medical condition may be linked to the incident on Monday."
Police appealed to anyone with information about the incident to come forward.
^ Back to top | BBC Sport Home | BBC Homepage | Contact us | Help | ©