Nadine Flood is stepping down as national secretary of the Community and Public Sector Union.

After ten years, Ms Flood says it was a difficult decision, but she needed to listen to her doctors.

“At the moment, doing this job means I can't take care of my health the way I need to, and I've decided it's time to take the advice of my doctors and step back,” she wrote in an email to staff and members.

“I'm hopeful that if I stop ignoring my doctors' advice I can look forward to getting well and going on to do work that helps working people and keep fighting for the values I hold dear.”

The CPSU governing council will meet in three weeks to appoint an acting national secretary. Ms Flood will help the transition to the new national secretary before officially leaving.

Assistant national secretary Michael Tull paid tribute to Ms Flood as a “phenomenal leader”.

“Over the last nine years and six prime ministers, she has led the union as we fought for better wages, conditions, jobs, and for our community's services. Her defence of our members and the public service has always been fearless and forthright,” he said.

“She will leave behind her a united Executive and a union that is well placed to continue the work of representing our members in their workplaces and in the community.

“While we are sad to see her go, it's important she place her health first and we respect her decision, which we know has not been an easy one.”