United Kingdom, May 24 -- Chrissy Teigen has undergone a "hairline lowering procedure".

The 39-year-old model has taken to social media to explain a photograph in which she's seen wearing bandages around her head and with what appeared to be a swollen face.

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 ...