Andy
Retired committee member
No idea who Gigi Hadid is but she has Hashimoto's Disease apparently.
http://www.bbc.co.uk/news/newsbeat-43029158"Imagine having a really extreme case of flu."
That's how 23-year-old Rachel Hill describes living with Hashimoto's disease.
She's been talking to Newsbeat about the thyroid condition she shares with Gigi Hadid - who's hit back at trolls who've criticised her appearance.
The model says her weight loss is due to the treatment she's now getting for the disease.
The NHS describes it as being "caused by the immune system attacking the thyroid gland, making it swell and become damaged".
This can lead to "tiredness, weight gain and dry skin". There is no cure and it can take months or years to be diagnosed.