02/12/2008 at 10:00 AM EST
Lenny Kravitz was rushed to Miami's Mount Sinai Hospital on Monday, a spokeswoman for the singer confirmed to Reuters.
The rocker, 43, had been stricken with a series of severe respiratory tract infections combined with the flu since mid-January.
"Due to extreme dehydration and fatigue, doctors were unable to control it with outpatient treatment and advised the singer to check into the hospital," Kravitz's spokeswoman said in a statement.
The condition has forced the postponement of Kravitz's European tour to promote his new album It Is Time For a Love Revolution.
– Caris Davis