Marion Braine, aged 58, from Hatfield in Hertfordshire, was treated in a mixed-sex ward seven years ago. She said the experience was "terrifying".
"About seven years ago I had cellulitis (a skin infection) in my legs and I went into hospital for treatment. The ward had men down one end and women down the other.
"I didn't feel at all comfortable because there were men there. You weren't properly dressed and sometimes they did procedures at your bedside and the curtains weren't properly closed so they could see you.
"There was a man who kept coming up the ward and sitting on my bed. I asked the nurse if she would stop him coming up and she said, 'No'.
"A couple of times he was walking along with no trousers and no underwear, which was embarrassing.
"One time he got quite aggressive. He said, 'I'll sit here if I want to sit here.'
"The nurse just said that the gentleman was mentally ill and it wasn't his fault. She said she couldn't keep him at his end of the ward.
"It was terrifying. I felt like I couldn't go to asleep in case he ended up sitting on my bed. I was totally relieved to leave hospital.
"In the end they put him on another ward, which I think they should have done in the first place. I think the ward is still like that - I don't know why.
"It's very uncomfortable. You wouldn't expect a man to come into your bedroom would you? I would like to see proper (single sex) men and women wards only."