Alliance leader Naomi Long is going into hospital today for surgery to address a long-term illness.
Mrs Long revealed that she suffers from aggressive endometriosis which causes excruciating pelvic pain and heavy bleeding.
The condition involves tissue normally lining the womb growing outside it and can have a huge impact on quality of life.
The East Belfast MLA wrote on Facebook that she had suffered the condition most of her adult life. "However, the chronic pain and other symptoms of the condition have become increasingly severe and hard to manage over the last few years, resulting in a couple of emergency admissions to hospital," she wrote.
"It has generally become quite debilitating, so I've decided that surgery is now the best option."
Mrs Long said she had postponed surgery in January after Stormont collapsed and the Assembly election was called, and again in April due to the Westminster election and talks process.
"However, I now need to put my health first and am hopefully having my operation on Tuesday," she said. "It's routine but quite big surgery, with a slow recovery time, so I will be off work for about 8-10 weeks recuperating.
"I will also be taking a social media break for at least some of that time, though maybe not all of it!"