What Causes Pulsating Pain In Ankle At Night?

Iam inquiring about recent ankle pain that started two days ago, after an active evening playing racquet ball. I came home and that night had severe throbbing on my right ankle only, throughout the whole night. In the morning it was fine, even did my sprints and it did not hurt whatsoever. However, again last night I was kept up by a throbbing, pulsating pain in the same ankle. And now it's gone again. But the pain was severe.