Lena Dunham in hospital and undergoing surgery after ovarian cyst ruptures

The New York-born Girls’ creator and actress has frequently spoken candidly about her health problems on social media (Getty)

Girls star Lena Dunham is in hospital after rupturing an ovarian cyst and is due to undergo surgery.

The 29-year-old American actress has endometriosis, a painful female reproductive disease that occurs when tissue that normally grows inside the uterus grows outside of it.

“Lena Dunham has been very public with her personal bouts with endometriosis," her spokesperson, Cindi Berger, told The Hollywood Reporter.

"This morning, she suffered from an ovarian cyst rupture and has been taken to the hospital.

“Lena will be undergoing surgery at an undisclosed hospital. We thank you for your understanding and hope that Lena's privacy will be respected.”

The New York-born Girls’ creator and actress has frequently spoken candidly about her health problems on social media.

In February, Dunham took to Facebook to inform fans she would not be able to do press for the fifth season of Girls due to endometriosis.

“I just wanted to let you know that, while I am so excited for Girls to return on Feb 21, I won't be out and about doing press for the new season," she wrote

"As many of you know I have endometriosis, a chronic condition that affects approximately 1 in 10 women's reproductive health.

“I am currently going through a rough patch with the illness and my body (along with my amazing doctors) let me know, in no uncertain terms, that it's time to rest.

“That's a hard thing to do, but I'm trying, because all I want is to make season 6 of Girls the best one yet."

Endometriosis can be a source of infertility and can cause side effects that can be life-threatening if left untreated.

Dunham underwent surgery for the disease last November, choosing to document her experience in her Lenny Letter, an email newsletter launched by Dunham and co-producer Jenni Konner.

“The first day, I felt exactly as Randy had predicted I would: 'Like Mohammed Ali punched ya in the tummy!' But two days after the surgery, I was better than I had been in 10 years,” wrote Dunham.

“The illness, nausea, heaviness, and fatigue were replaced by an alien absence of sensation. Is this what it's like to have a body? I wondered. A regular body?”