United Kingdom, Jan. 9 -- Gwyneth Paltrow failed to call an ambulance when she suffered "heart attack" symptoms because she didn't know the emergency services number.

The Hollywood actress, 53, has revealed her health suffered following the death of her father Bruce Paltrow in 2002 and the grief led to a terrifying incident in which she woke up in the middle of the night fearing she was having cardiac issues - but she wasn't able to call for help because she was in London and didn't know the UK uses 999 instead of 911.

During an appearance on The Hollywood Reporter's Awards Chatter podcast, Gwyneth explained: "I felt like I was going to die of grief ... There was one night where I woke up and I thought I was having a heart attack in Lon...