My daughters boyfriend has extremely high levels of Co2 in his blood stream.....he was tested out at 3.5.  They checked the house out and everything was ok.  What could be other causes?  He usually is away at college but is home for the summer so there are two different locations too.  He does not smoke either....it is a little confusing...
Hi, Thanks for using Chat Doctor. Kindly put the values in units and also other values tested. Since most carbon dioxide is present in the form of bicarbonate, which is regulated by the lungs and kidneys. The value indicate of how well the kidneys and lungs are managing the bicarbonate level in the blood. . There are multiple reason for raised CO2 level in his blood. So if you can put his other investigations reports, why he got done the investigation(problem) then we can discuss in detail W.R.T his problem. Breathing exercises will be good for him. Hope I answered your question. Feel free to ask me if you have any further queries or doubts and I shall be glad to help you out. Wish you good health. Take care. Regards