Former Liverpool midfielder Jay Spearing has been diagnosed with a rare disorder of the adrenal glands after being rushed to hospital on Saturday.
The 34-year-old, who made 55 appearances for the Reds between 2008 and 2013, has been working as an age-grade coach at Liverpool.
He is one of about 300 new cases of Addison's Disease each year in the UK.
"Don't ignore changes in your body, no matter how small, get them checked out!" he wrote on Instagram.
Blood tests by Liverpool's medical department revealed he was close to falling into adrenal crisis, a potentially fatal condition caused by a drop in the cortisol hormone.