Amy Winehouse collapsed at her house in Barnet, North London due to nervous exhaustion.
A doctor was reportedly called out over Christmas to treat the singer.
A friend of the 26-year-old said she had already had a serious chest infection before the stress of her recent arrest took its toll.
"She's been told to keep a low profile and fully recuperate. She has been feeling very ill of late and had a funny turn at home. She is quite unwell and exhausted after recent events but is soldiering on," the Mirror quoted a pal as saying.
According to her friends, the singer is not drinking too much or taking drugs.
"She's doing her best to concentrate on her music and not become embroiled in drugs again. Her new songs are amazing but will be on the back burner until she feels better," the pal said.
Winehouse was charged with a public order offence and common assault over a bust-up with a man during a pantomime in Milton Keynes, Bucks.
She allegedly lashed out at a theatre manager, 27, after disrupting a performance of Cinderella.
Winehouse will appear at Milton Keynes magistrates' court on January 20.
The source said: "The last week has been a massive setback for Amy who was really turning a corner. Everyone in her camp is shocked by what has happened.
"But their main concern is making sure she feels better. Then she can throw herself into her music.
"The New Year isn't getting off to the best start but Amy is determined and she'll keep looking forward," the source added.