The 67-year-old guitarist fell sick following the band's show in Paris, France last week (beg26Jan15), and has been struggling with ill health ever since.
May admits he barely made it through concerts in Cologne, Germany and Amsterdam in the Netherlands, but he has refused to bow out of any of the group's gigs.
In a post on his blog after the Cologne show on Thursday (29Jan15), he writes, "I have seldom felt so ill and yet still played a gig - as tonight. Somehow I got flu on the day after Paris - and today the high temperature, the headache, and the sinus blockage made me doubt I could even keep upright, never mind play a show. But in the event, adrenaline and the warm energy of the audience got me through."
However, May felt no better when he took to the stage on Holland on Friday (30Jan15), writing afterwards, "I took so much Neurofen (painkiller) to get through the night I definitely forgot where I was somewhere around Crazy Little Thing... and by (Bohemian) Rhapsody I was hangin' on by my fingernails."
May made a slight recovery over the weekend (31Jan-01Feb15), and he thanked fans for their well wishes in a post on Twitter.com, writing, "Thanks for the get well messages, folks. I kinda didn't exist for the past 36 hours. I think I survived."