Chrissy Teigen has opened up about her battle with postpartum depression.

Chrissy Teigen and John Legend

Chrissy Teigen and John Legend

The 'Sports Illustrated' model - who has 10-month-old daughter Luna with her husband John Legend - felt her life changed after she welcomed her little girl into the world but couldn't "figure out why" for so long.

She shared: "I went back to work on 'Lip Sync Battle' in August, when Luna was four months. The show treated me incredibly well ... But I was different than before. Getting out of bed to get to set on time was painful. My lower back throbbed; my ­shoulders - even my wrists - hurt. I didn't have an appetite. I would go two days without a bite of food, and you know how big of a deal food is for me. One thing that really got me was just how short I was with people.

"I would be in my dressing room, sitting in a robe, getting hair and makeup done, and a crew member would knock on the door and ask, 'Chrissy, do you know the lyrics to this song?' And I would lose it ... They would leave. My eyes would well up and I would burst into tears. My makeup artist would pat them dry and give me a few minutes.

"I couldn't figure out why I was so unhappy. I blamed it on being tired and possibly growing out of the role, 'Maybe I'm just not a goofy person anymore. Maybe I'm just supposed to be a mom.'"

And the 31-year-old model's feelings of depression and anxiety left her unable to muster up the energy to leave the house.

She added: "When I wasn't in the studio, I never left the house. I mean, never. Not even a tiptoe outside. I'd ask people who came inside why they were wet. Was it raining? How would I know - I had every shade closed.

"Most days were spent on the exact same spot on the couch and rarely would I muster up the energy to make it upstairs for bed. John would sleep on the couch with me, sometimes four nights in a row. I started keeping robes and comfy clothes in the pantry so I wouldn't have to go upstairs when John went to work. There was a lot of spontaneous crying."

However, Chrissy finally saw a light at the end of the tunnel when she visited her GP and got diagnosed.

In a revealing essay for the April issue of Glamour magazine, she shared: "Before the holidays I went to my GP for a physical. John sat next to me. I looked at my doctor, and my eyes welled up because I was so tired of being in pain ... My doctor pulled out a book and started listing symptoms. And I was like, 'Yep, yep, yep.' I got my diagnosis: postpartum depression and anxiety ...

"I remember being so exhausted but happy to know that we could finally get on the path of getting better. John had that same excitement. I started taking an antidepressant, which helped. And I started sharing the news with friends and family - I felt like everyone deserved an explanation, and I didn't know how else to say it other than the only way I know: just saying it. It got easier and easier to say it aloud every time."