Chrissy Teigen has undergone a "hairline lowering procedure"

Chrissy - who has been married to music star John Legend since 2013 - wrote on Instagram: "Hi friends! A lot of you worried about my hospital pic which is very understandable as I gave no explanation lol I had a hairline lowering procedure. Lost a lot in the front from babies and it's just very thin up there. When you see it on a carpet, it's ALWAYS extensions. (sic)"

Chrissy suggested that she'll reveal more about the procedure in the coming days and weeks.

She said: "Anyhow I'll share more later if you're interested in the journey because it really is a journey (sic)"

Chrissy has previously admitted to having undergone various cosmetic procedures.

The former Sports Illustrated Swimsuit star actually joked that almost everything about her face was "fake".

Speaking to Byrdie in 2017, Chrissy quipped: "Everything about me is fake except my cheeks. Fake, fake, fake."

Chrissy has no regrets about any of the cosmetic work that she's had done in the past.

The model explained: "I'm not shy talking about that sort of thing. I have no regrets."

What's more, Chrissy opened up about one of the more extreme procedures she's been through.

The runway star shared: "I had my armpit sucked out.

"It added two inches of length to my arms ... [that fat] is coming back though, so I might need to go in and pay for it again."

Chrissy subsequently took to X to clarify her comments, insisting that she was just joking about the extent of the work she's had done.

The model - who has developed a reputation for being open and honest with her social media followers - said at the time: "Reminder to never ever joke, ever (I did do the armpits, no regrets except it clearly came back). You think I'd have this a** if I'd done extensive work? Like who would ask for this a** [laughing emoji] (sic)"