If your expriencing chronic discomfort be aware of the possibility of carpal tunnel syndrome, that comes from chronic hyperextension of the wrist.

Get a professional guitarist or classical instructor to show you the proper techniques for reducing stress on the wrist.

Seriously. A severe case of carpal tunnel can involve chronic pain, numbness, loss of strenght and loss of control, particularly in the distal (outer) fingers. I've had it (a combination of guitar and riding a bicycle an leaning on the handlbars without gloves).