Taiwanese singer Angela Chang’s Chengdu concert on August 23 took an unexpected turn when she suddenly fell ill mid-show.

The 44-year-old was performing her 2007 hit Doesn't Hurt when fans noticed something seemed off.

She was seen repeatedly tugging at her collar and the hem of her skirt, leading some to suspect that she was feeling unwell.

Her condition then appeared to worsen, forcing the concert to be temporarily halted.

Videos circulating online show Angela looking visibly unwell as medical staff attended to her on stage. They took her blood pressure, fanned her, massaged her hand and fitted her with a nasal oxygen cannula.

At one point, a tearful Angela appeared on the venue's big screen, before the message: “I’m sorry, please give me three minutes” flashed across it.

Some fans initially thought the interruption was part of the show, only realising something was wrong when they saw Angela being attended to by medical staff.

After a short rest, Angela returned to the stage and continued with the concert.

She later explained to the audience that she had started feeling unwell after changing into a heavy carousel-themed costume.

“Maybe it was because of the hot weather, maybe it was because the costume was heavy,” she said, adding that she felt her heart was struggling to cope after putting it on.

An emotional Angela apologised for making everyone wait and worry, and assured fans that she wouldn't force herself to carry on if she really couldn't.

Angela has previously spoken about her heart condition.

In 2008, she was diagnosed with mitral valve prolapse and took several months off work to seek medical treatment in Canada.

Later that night, Angela took to Weibo to assure everyone she was okay.

She said a medical team had been present throughout the concert and thanked them for quickly monitoring her condition and taking the necessary measures.

Angela also underwent a more comprehensive examination after the show.

“Everything is fine at the moment,” she wrote. “Thank you to everyone for your concern. Please don't worry about me.”

Angela is scheduled to perform next in Guiyang on Aug 29.

Staff took Angela's blood pressure, massaged her and fitted her with a nasal oxygen cannula.

Photos: super_william/Instagram, 张韶涵/Weibo, 新浪娱乐/Weibo