could be hyperhidrosis.
Nothing to worry about health wise really, i sweat like a mad man very easily too, its good when doing circuit training because everyone thinks your working 10 times harder than you actually are ... not so good on a run when 5 minutes after you've started your t shirt is soaked through, just make sure you keep yourself hydrated well.
Some people say its lack of fitness and such, utter *******s, a friends of mine sweats just like me, yet one of the fittest blokes i know, he recently passed his RE diver course too.