Olympic gold medallist Alex Danson-Bennett has retired from hockey because of long-term concussion.
The former Great Britain and England captain, 34, hit her head on a wall on holiday in 2018.
She returned to the Great Britain set-up in January after 18 months out in a bid to make the Tokyo 2020 Olympics but says the "risk is too high".
"After a long 18 months but a fabulous 18 years in the sport, it's the right time for me to retire," she said.
"It's been the most incredible journey I could have asked for, but a lot has changed. My head injury has been life-changing, also in terms of my perspective and things that have happened within my family.
"Throughout my career I've been 100% immersed in being an athlete, but my priorities are different now. All of that means it's the right time.
"I've known over the last couple of weeks that it was a decision I needed to come to. It's difficult because this has been my life. It'll be strange moving into something new, but I'm totally thankful and content. I have zero regrets about the way I've lived my career."
Forward Danson-Bennett was part of the Great Britain team that won gold at the Rio Olympics in 2016.
She won 306 total caps for England and Great Britain and scored a joint-record 115 goals combined, level with Marjorie Pollard.
'This is not a sad retirement - I lived my dream'
Danson-Bennett's final international appearance was England's World Cup quarter-final defeat by the Netherlands in August 2018.
Weeks later, Danson-Bennett sustained a mild traumatic brain injury after hitting her head on a concrete wall while laughing at her now husband Alex's joke on holiday in Kenya.
In the months that followed the accident, Danson-Bennett spoke of "losing her identity", as she experienced debilitating headaches, light sensitivity and loss of speech.
In October, just over a year after the incident, she celebrated being able to jog for 30 minutes for the first time.
She returned to training with the rest of the players on the centralised programme in January, saying she was "still not 100%" but "time was running out" before the Tokyo Olympics in July.
"The challenge of returning to play following my head injury is too much, and the risk's too high," she wrote on Instagram.
"This is not a sad retirement. I have played more games in more tournaments than I could ever have dreamt of. I have made lifelong friends, travelled the world and loved every single minute of my career.
"I end my playing days completely content, proud of how I committed every day for 18 years and thankful to have had the most incredible people by my side. I look back and have not one single regret. I lived my dream."
'Alex is a truly special person'
Danson-Bennett, who played for Clifton Robinsons, Reading, Slough and Dutch club Klein Zwitserland during her career, made her England debut against Germany in 2001 at the age of 16.
Representing England, she won the 2015 European Championship, bronze at the 2010 World Cup and claimed one silver and three bronze Commonwealth Games medals.
With Great Britain, she also won bronze at the London 2012 Olympics and silver in the Champions Trophy the same year.
She was named temporary England captain in July 2017 before being appointed permanent England and GB captain in November that year.
Danson-Bennett was appointed MBE in the 2017 New Year Honours for services to hockey.
GB Hockey performance director Ed Barney said: "She has been an inspirational figure to all those who have worked with her, to those who have had the fortune to play with her and to many who have watched her exhilarating performances.
"Alex is a truly special person. It is impossible to find the right words to reflect how fortunate we have been to have Alex as part of our sport. We will miss her hugely both on and off the pitch."
Danson-Bennett's triathlete sister Claire was paralysed from her stomach down after colliding with a tractor when riding her bike in August last year.