Olympic champion Kelly Holmes said she cut herself every day as she battled with depression and the worry that her injuries would ruin her career.
Ms Holmes said just a year before she won gold in the 800m and 1,500m competitions in Athens in 2004 that she was self-harming “to release the anguish”.
“At my lowest, I was cutting myself with scissors every day that I was injured."
At the Health and Wellbeing Live show in Tunbridge Wells this weekend Dame Holmes showed a picture of one of her injuries she took during the world championships in 1997.
It was one of seven injuries that led to her self-harming.
“The scissors were in the bathroom and I used them to release the anguish that I had. It was really a bad place to be,” she told the BBC.
”But my biggest message to people is that you can get out of that and you can still achieve.
“There is always a light at the end of the tunnel.”
She also wrote: “We need to smash the stigma and encourage people to talk about their feelings: whether that’s depression, felling of isolation, overwhelming sadness, a desire to self-harm or an already established pattern.
“Mental health takes many forms and manifests in many ways.”
She said Prince Harry was “brave” for speaking about his own mental health challenges in an effort to make the issue more mainstream and “acceptable”.
Becky Randall, co-founder of Health & Wellbeing Live, said: "[Holmes] struggled but she kept going.
”So many of us are inhibited by a black cloud that sometimes descends, by feeling not good enough.
“I want people to be able to understand that they are not alone and that talking about it is what really helps. It's got to be out there.”
You can contact the Samaritans by calling them for free from any phone for free on 116 123, email jo@samaritans.org or visit www.samaritans.org to find details of your nearest branch.
