The Ace of Spades hitmaker has been out of action for some time after undergoing heart surgery and suffering a "severe haematoma", which prompted the group to axe a European tour earlier this year (13).
The group returned to the stage at a music festival in Germany on Friday (02Aug13), but the show was cut short as the ailing frontman was too weak to continue - sparking fresh fears for Lemmy's wellbeing.
However, his friend Slash visited him on Tuesday (06Aug13), and the former Guns N' Roses star has told fans Lemmy is recovering well.
In a post on Twitter.com, he writes, "Visited Lemmy today; he's doing well. There's been a lot of rumours. But he's in good shape. (And) finishing Motorhead record now."