A rolled ankle is characterized by the outer or inner side of the ankle giving way, and may be a recurring problem due to an injury or deformity. Usually, the ankle gives way while walking or during other activities, but it can also happen while just standing.
Usually due to an underlying injury, ankle pain refers to any kind of sudden or worsening discomfort affecting any part of the ankle.
An ankle sprain refers to tearing of the ligaments of the ankle. The most common ankle sprain occurs on the lateral (outside) part of the ankle.
Instability is the inability of a joint to support weight or maintain balance, a feat which requires coordination between functional ligaments and tendons.
Foot drop is a general term for difficulty lifting the front part of the foot, which might even drag on the ground while walking.
High Ankle Sprain
The high ankle ligaments are located above the ankle, as opposed to the more commonly injured ligaments on the outside of the ankle.