Emergency services were called after a blue Ford Mondeo crashed into a barrier on the hard shoulder near junction 32 at around 11.10am.
The driver was taken to Royal Preston Hospital by ambulance after suffering a 'medical episode' at the wheel, say police.
North West Ambulance Service said the man is believed to have lost control of his vehicle after falling ill on the northbound carriageway near Broughton Interchange, where the M6 meets the M55.
A spokesperson for Lancashire Police said: "At around 10.50am we were called to reports of a collision with a blue Ford Mondeo and the barrier on the hard shoulder."
He remains in hospital where is being treated for serious injuries sustained in the crash.
The crash led to delays on the northbound M6 for around an hour, with lane 1 closed whilst emergency services attended the scene.
Last night (Tuesday, August 11), shortly before midnight, a man was killed in a crash in Yew Tree Road, Blackburn.
Police said a man had been pronounced dead at the scene and an investigation is underway today to establish what happened.
Yew Tree Road remains closed this morning.