Hello. Have you had a foot & ankle examination by an orthopaedic surgeon to ensure there is no fracture? Sometimes you may need an xray. If fracture is ruled out & a diagnosis of sprain is confirmed clinically, then initial treatment is careful mobilisation with ankle exercises (physiotherapy) to promote healing. Immobilisation in a cast is only required in a severe (grade 2/3) sprain to give an initial period of rest up to 10-12 days. If you continue to have instability (recurrent twisting), then a further clinical assessment is required to assess need for an MR scan. A rare but significant injury is when recurrent instability is a result of complete rupture of ligaments around ankle- and this requires surgical reconstruction of ligaments but is not an emergency operation.
Next Steps
Please see an orthopaedic surgeon.