Actress Lena Dunham has opened up about her painful struggle with endometriosis in a heartbreaking new blog article.

The Girls star has detailed her symptoms of non-stop vaginal bleeding, cramps and chronic exhaustion in the latest edition of her weekly newsletter, Lenny Letter.

"From the first time I got my period, it didn't feel right," she recalls. "The stomach aches began quickly and were more severe than the mild-irritant cramps seemed to be for the blonde women in pink-hued Midol commercials. Those might as well have been ads for yogurt or the ocean, that's how little they conveyed my experience of menstruating."

Dunham reveals her symptoms went undiagnosed throughout her teen years, and she was still in pain from the disorder, which causes the lining of the uterus to grow outside of the uterus, while she was shooting the first season of Girls.

"If my pain had no tangible source, that just meant my mind was more powerful than I was and it didn't want me to be happy, ever," she adds. "I saw myself divided like a black-and-white cookie into neat halves: one bright and ambitious, the other destined to wind up strapped to a gurney and moaning for pain meds."

A chance encounter with a friend's doctor, Dr. Randy Harris, turned her life around.

The medic performed laparoscopic surgery to diagnose Dunham, who now takes monthly injections to control her symptoms.

Dunham admits she's now glad she went through all the pain - because endometriosis has made her one of the strongest women she knows.

"I am strong because of what I've dealt with," she explains. "I am oddly fearless for a wimp with no upper-body strength, and I am no longer scared of my body. In fact, I listen to it when it speaks. I have no choice but to respect what it tells me, to respect the strength of its voice and the truth of my own."