Sweden and FC Midtjylland midfielder Kristoffer Olsson is on a ventilator in hospital in Denmark suffering from a brain disease, the club said on Tuesday.

Midtjylland said Olsson, 30, lost consciousness at his home last week and has since been treated at Aarhus University Hospital. The club said his hospital admission was "not caused by self-harm of any kind, nor is the cause due to external factors."

Midtjylland added: "A team of Denmark's leading medical experts is currently working at high pressure to make a diagnosis and initiate the right treatment."

"Since admission, Kristoffer has been surrounded by his immediate family and parts of FC Midtjylland's staff, and is being treated by specialists in the field.

"FC Midtjylland urgently requests the public to show respect and understanding, so that Kristoffer, the family and the doctors get the necessary peace of mind to ensure Kristoffer's recovery and recovery as well as possible."

Midtjylland said it was "forced" to release the information about Olsson because of "increasing rumors" about his absence from the team.

Olsson graduated from Arsenal's youth academy in 2013 but did not make a senior appearance for the club.

He joined Midtjylland in 2015 before leaving for spells at AIK, Krasnodar and Anderlecht. He returned to the club on loan in 2022 before making his return permanent last summer.

Olsson has 47 caps for Sweden and represented the country at the European Championship in 2021.

"We're with you, Koffe," Sweden's Football Association said in a post on X.

"On Tuesday morning, we received the terrible news that men's national team player Kristoffer Olsson suffered a sudden illness and is now on a ventilator in hospital.

"The entire Swedish football family is thinking of you and hopes that you will recover soon. Our thoughts also go to Kristoffer's loved ones at this difficult time."