The ambulance service was called because the driver was complaining of chest pain, say police.
A spokesman for West Mercia Police said: "We were called at 1.49am on Saturday to Forton Road roundabout close to McDonalds.
"A 44 tonne articulated had overshot and gone straight through the roundabout ending up on the roundabout in a wooded area. A tree branch had gone through the windscreen."
The spokesman said the ambulance service were called because the driver was complaining of chest pain.
The police said the road was closed because the lorry had to be recovered from the scene of the crash.
"The road was shut while the lorry was recovered which required three recovery wagons," the spokesman said.
"The road was not re-opened until after 9am."
A spokesman for West Midlands Ambulance Service said: "We were called at 1.54am on Saturday to a road traffic collision involving a HGV on Forton Road Roundabout in Newport.
"One ambulance attended the scene. Upon arrival we found a man who was the driver of the HGV. He was assessed by ambulance staff and was in a potentially serious condition.
"He received treatment from ambulance staff and was conveyed to Princess Royal Hospital for further assessment.”