NFL Media Insider Ian Rapoport reported Monday on NFL Network's "NFL Total Access" that Kubiak suffered what doctors refer to as a mini-stroke when he collapsed on the Reliant Stadium sideline during halftime, according to sources with direct knowledge of the coach's condition.
The official diagnosis is that Kubiak suffered a TIA, or transient ischemic attack, which occurs when a blood clot blocks an artery for a short time and affects blood flow in the brain.
A TIA involves temporary but reversible loss of function, and doctors tell Rapoport there are no residual effects. A TIA is considered to be a warning that blood flow is not what it should be and can be seen as a precursor for a larger stroke.
"It is treatable, which seems to be the reason for the optimism when you talk to Texans people," Rapoport said.
It remains unclear how long Kubiak will be away from the team, but the coach's diagnosis counts as good news in the relative sense.