The Public Health Protection Unit of NHS Greater Glasgow and Clyde (NHSGGC) is investigating seven cases of E.coli O157 which could be linked to the consumption of burgers at the Hydro.
Other food items are also being considered.
NHSGGC is liaising with other health boards, Health Protection Scotland, the Food Standards Agency and Glasgow City Council Environmental Health in its investigation.
All seven people affected are recovering at home.
One of the cases is from the NHSGGC area, two are from the NHS Lanarkshire area, three from NHS Lothian and one is from Cumbria.
Dr Gillian Penrice, consultant in Public Health Medicine at NHSGGC, said: "We are pleased that all the cases are recovering at home.
"Investigations are under way to identify if there is any common source.
"While there is no conclusive evidence our initial investigations have indicated that there may be a link to the consumption of burgers at the SSE Hydro and Glasgow City Council Environmental Health Officers are working closely with the vendors to ensure all appropriate food hygiene standards are being met.
"I would ask anyone who has attended the Hydro recently and who has experienced or is continuing to experience symptoms including stomach cramps, diarrhoea (often bloody), nausea and fever to contact their GP."
NHSGCC is asking anyone who attended the Hydro between Friday, January 17 and Saturday, January 25 and has experienced, or is continuing to experience, symptoms including stomach cramps, diarrhoea, nausea and fever they should contact a GP or NHS out of hours service.
The Hydro held events including Top Gear over three days, Del Amitri and Celtic Connections during the period under investigation.
A spokesman for the Hydro said: "“We have been contacted by the Environmental Health in relation to an investigation into an e-coli outbreak which they believe may have been connected to one of the catering outlets on our premises.
"We are awaiting further details to establish the exact cause of this isolated incident and our catering partners have been working closely with environmental health officers.
"The initial review of our caterers standard procedures have been found to be satisfactory and EHO have seen nothing in their processes and practices which concerns them.
"We wish to assure the public that at this time we have no significant concerns in relation to catering for our patrons.”