Police were called to the Dartford Crossing at around 3.20am on March 4 after concerns for the welfare of a woman.
Officers say she was left in the care of health professionals.
At around 4am National Highways said that traffic was stopped on the approach to the crossing.
It reopened again at around 4.50am, with delays of 20 minutes.
A spokesperson for Essex Police said: “We were called to concerns for the welfare of a woman on the Dartford Crossing at around 3.20am today (Monday 4 March).
“Emergency services attended and the woman was left in the care of health professionals.”
