My wrist has really been hurting for no apparent reason right underneath the thumb area. any ideas?

Thumb pain: Pain at the joint of the base of the thumb is commonly seen in degenerative arthritis, but you are too young to be getting that. So, possibly you have a mild tendonitis, also overuse injury from computing or typing can lead to hand/wrist/finger pains from injuring the small bones of the hands or straining the ligaments in the hand/wrist.