The incident occurred on Bristol Road in Stonehouse with police saying the driver suffered a suspected medical episode.
The road was shut just after 6am and reopened two hours later.
A police spokesperson said: “We were called to Bristol Road in Stonehouse shortly before 6.10am with a report of a single vehicle collision.
“The driver of a van was taken to Gloucestershire Royal Hospital for treatment after a suspected medical episode.
“Bristol Road was closed while emergency services were at the scene and reopened at around 8.10am.”