Symptoms include abnormally painful periods, ones Dunham experienced from the time she first began menstruating, she wrote.
From the first time I got my period, it didnt feel right, she said.
Dunham ended the piece by clarifying that endometriosis is not life-threatening and wrote about how it changed her life.

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But I am strongbecauseof what Ive dealt with … And I am no longer scared of my body.
In fact, I listen to it when it speaks.
Read the full essayhereand see her Facebook post below.Girls fifth seasonpremieres Feb. 21 at 10 p.m.