The accident happened on Sussex Road, at the junction with Ashenground Road and Franklynn Road, before midday today.
A West Sussex Fire and Rescue Service spokesman said they were called to the scene by Sussex Police at 11.37am, and sent two heavy rescue vehicles.
When they arrived at the scene, paramedics had already got her out of her vehicle. She was taken to hospital, the fire service spokesman confirmed.
Firefighters left the scene at 12.45pm.
Sussex Police attended the scene and closed off part of the road while the emergency services dealt with the incident.
A police spokesman was unable to find the details of the accident.