I have really sweaty hands, what can i do to prevent it?

Hyperhidrosis: Increased sweating or hyperhidrosis is common: http://dermnetnz.Org/hair-nails-sweat/hyperhidrosis.Html there are prescription antiperspirants that may help. Injection with botulinum toxin can also stop the sweating temporarily. If it is more widespread or not responding to the topicals, there are systemic medications that can decrease sweating. Your dermatologist will help guide you.

Palmar hyperhydrosis: If hyperhydrosis, surgery can be quite successful for appropriate candidates. While done often by experienced thoracic surgeons (vats), it is chest surgery (major surgery). There are risks and benefits. Appropriate candidates should be selected. This link to consensus: http://goo.Gl/voqx5.