Wattie Buchan was taken to hospital after falling ill during The Exploited’s gig in Lisbon on Thursday night.
A statement on the band’s Facebook page said: “We are sorry to say that due to a severe illness that Wattie can't continue with the tour. He will be in hospital for at least a week. Thanks for all the get-well messages.”
The 57-year-old from Edinburgh founded the band in East Kilbride in 1980 and had been working on a new album, the first in 11 years, which is due out this year.
His illness comes a week into the seven-month “Tour of Chaos” with Hatebreed and Napalm Death. Other cities on the tour include Barcelona, Paris, Stockholm and Glasgow.
The band has cancelled all activities until May in the wake of Buchan’s illness.