Charles Kennedy died from a "major haemorrhage" caused by his alcohol addiction, his family has said.
The former Liberal Democrat leader died aged 55 at his home in Fort William on Monday after battling with his drink problem.
Details surrounding the cause of his death were revealed by his family today following a post-mortem examination.
In a statement, they said: "We are grateful to the many friends and also medical experts who sought to help down the years but ultimately this was an illness Charles could not conquer despite all the efforts he and others made.
"We can now proceed to make arrangements for his funeral and we will make an announcement on the details in due course."
Shortly after leading his party to its greatest success in the 2005 general election, Mr Kennedy revealed he had been receiving treatment for an alcohol problem.
He was later forced to stand down as senior colleagues threatened to resign.
Speaking publicly about his battle with addiction in 2006, he said: "I chose not to acknowledge it publicly before in this way because, if at all possible, I wanted to overcome it privately.
"I learned the hard way of the need to face up to this medical problem, one that is dealt with successfully by many others on a daily basis."
This week, Mr Kennedy's ex-wife Sarah and 10-year-old son Donald attended a special session in the House of Commons to hear MPs pay tribute to their popular former colleague.
His family said today they had been "touched beyond measure by the outpouring of warmth" from all parts of the country following his death.
They said: "The pain we feel has been at least eased somewhat by the reaction of so many people across Scotland, the UK and beyond, and by the affection expressed by politicians across the spectrum. It has become all too apparent to us how much Charles meant to so many people and how many lives he touched."
Additional reporting by the Press Association
