Paramedics were called to the scene on Cinder Bank, Netherton, just after 7.30am this morning.
A man had fallen ill at the wheel of a van and crashed into three other vehicles.
He was treated at the hospital and discharged at the scene.
No-one else was injured.
A West Midlands Ambulance Service spokesman said: “We were called to reports of an RTC on Cinder Bank at 7.33am this morning.
"One ambulance attended the scene. On arrival, crews discovered a four-vehicle RTC.
"There was one patient, a man, who was the driver of a van.
"Crews were told the man suffered a suspected medical incident prior to the collision.
"He was assessed and treated on scene but did not wish to be taken to hospital, so was discharged at the scene.
"There were no other patients from the other three vehicles.”
West Midlands Police confirmed that now arrests were made.