Every time I take steps, my left ankle swells and hurts like a bruise. I've already had a sprain.

Hello,

In fact, this ankle may be more fragile because of your previous sprain. This one may not have healed well and therefore may be more prone to inflammation. It would be ideal to consult a physiotherapist to get the recommended exercises to heal this ankle. In the meantime, make sure you always walk in good shoes, limit the intensity and duration of your walks and wear a splint to compress (tighten) the ankle would help alleviate this weakness. You can use Voltaren gel locally or ibuprofen (Advil) to reduce inflammation. By seeing a specialist such as a physical therapist, you can probably fix the problem once and for all and no longer have this weakness.