Need help urgently

i do weight training, what happenes is when i stop for some time and then when i start if i do curls for the biceps when i sleep and get up the next day i can strech my arm, theres is feeling of tightness in my bicep and elbow and it hurts like hell and it looks a bit swollen, it happenes evry time when i start after not doing it for a while,
whats the best teatment normally it takes 3 to 4 days to heal, and y does this happen pls
thanx to any one who helps