Kerb Ramps

Hello
My car (Daewoo Lanos) is beginning to take the road surface when dropping off a sidewalk, or up one level on a multi-storey car park. He catches only in the back, and it is worse if there are people in the back. What could it be and how can I test this?
Thank you

It seems that you need new shocks in the rear. Might as well check the fronts and when you have set.

First, stop going on the edges. You're overloading your vehicle and caused damage to your springs and shocks!