EXTREME PAIN ON HAMSTRING??

I came home from running and i sat on my bed and wen i lifted my leg extreme pain shot threw my hamstring REALLY painfull pain.. then i rolled over and i felt a huge bump on on my hamstring and i was yelling wen like 5 secs ped and then the pain was gone(this isnt the first time but i dont want this to happen again is there something i can do)