Dave Mustaine knew Megadeth had to end after physical struggles working on their last album.

The 64-year-old guitarist has opened up on the legendary thrash metal band's recent self titled 17th and final LP - which was released on January 23 - and admitted the realisation it was the end came "halfway" through the process.

He told NME: "It was about the halfway point [of working on it]. My hands were hurting, and I'd already had issues with them because of arthritis.

"Then I had numbness from when my neck was fused together - my neck had been broken by a chiropractor - so I have a metal plate in my neck with some screws… so my hands were already messed up.

"I've always said that when I don't feel like I can do it anymore, that's going to be time for me to stop."

Dave admitted working in the studio was a "really difficult time", and he spoke to his management - which includes his son Justis Mustaine.

He recalled: "I spoke to him and I said, 'I don't know how much longer I can keep doing this'.

"He said, 'We should probably talk about it, because this tour is probably going to go for two, three, maybe four years. You're going to be a little bit older by that point… so what happens then?'

Dave explained the decision as "bittersweet", but one that his bandmates all supported.

He said: "I talked to the band and they were all super supportive.

"If I had said, 'Hey, I'm old and I don't want to do this anyway', that's one thing, but that's not the truth.

"I'm just keeping to my word about if I got to a point where I couldn't do my job 100 per cent, that I would discuss stopping. It's very bittersweet for me, but we made a great record and we're going out on top."