 -- Solange Knowles has pulled out of her New Year's Eve AfroPunk gig in Johannesburg, South Africa because of health issues.

The "Don't Touch My Hair" singer told her Instagram followers Wednesday that she's been battling an autonomic disorder and her doctor will not clear her to fly such a long distance to perform a "rigorous" show upon landing.

Knowles did not specify what her disorder is, but did say that it's a "complicated diagnosis."

"I can’t put into words how saddened and sorry I am that I am unable to perform for you guys this NYE, there is simply no other place I wanted to be than there with my family to bring in 2018 with you," she wrote. "I give you my ABSOLUTE WORD I will come back with AfroPunk and deliver this performance.....as it is so extremely important to me to connect with the people who have so closely inspired me in so many ways."

Knowles, 31, told her fans that opening up about her health was tough, as she wasn't sure how much to share. However, she did say that her health troubles have been "a journey that hasn't been easy on me," and noted that she's had her ups and downs.

According to the Mayo Clinic, autonomic nerve disorders affect the body's autonomic nervous system, which controls many of the body's involuntary functions including digestion.

Next year, Knowles said, she hopes to continue taking care of herself -- and to spend time with her fans.

"Performing this record and experiencing the energy exchange with you guys has been astounding, and I’m so excited about continuing to do the work," she wrote. "I feel so absolutely humbled and appreciative to be doing next year. It gives me life."