Thanks for posting your query.
According to your description , ankle pain and swelling seems to be inflammatory in nature. It can be due to acute episode of gout
I advice you to give you rest to your foot, take anti-inflammatory drug like motrin
1 tablet with food as and when required (upto 4 tablets daily) to reduce pain and inflammation and consult your doctor for thorough examination of ankle and foot and rule out any infective cause.
Wishing you good health
Dr Saurabh Gupta