Well there many different reasons due to which you could have big ankles, the primary one being that maybe you have a big body structure; hence you have big ankles and large feet to support that structure.
Another reason could be that maybe you have swollen up ankles due to muscle tightness. Swelling up of the ankles also takes place because of wearing high heels. Try wearing flat shoes, this will help reduce the ankle swelling and make them look normal. In the human body the ankle joint is shaped where the foot and the leg meet. The ankle also known as the talocrural joint basically is a synovial hinge joint which links the distal ends of the tibia to the fibula in the lower appendage and has the proximal end of the talus bone in the foot.
Another reason could be that maybe you have swollen up ankles due to muscle tightness. Swelling up of the ankles also takes place because of wearing high heels. Try wearing flat shoes, this will help reduce the ankle swelling and make them look normal. In the human body the ankle joint is shaped where the foot and the leg meet. The ankle also known as the talocrural joint basically is a synovial hinge joint which links the distal ends of the tibia to the fibula in the lower appendage and has the proximal end of the talus bone in the foot.