Board Thread:Wiki Discussions and Support/@comment-5090714-20150427053956/@comment-2043993-20180130152055

At the time of the 4th war, Hidan could technically still have been alive, but lack of nutrients and water would have made him practically useless in combat, his normal functions like thinking or even breathing properly would have been impaired to the point where he'd be considered comatose at best. But at the time of Naruto's appointment as Hokage(/Boruto's plot) I'd say it's more than likely that he's dead and gone forever.

To those that say he'd be dead before the 4th war because a human body can't survive that long withouth nutirents (let alone water), I'd like to remind you, that this is a fictional universe where (extremely skilled) characters can heal themselves after being cut in two or regenerate from only a few cells. Common logic doesn't always apply, especially if the plot doesn't call for it.