Thank you very much for the useful information Roger.
Well the usual causes for such kind of muscle cramps include an injury, exercise and physical exertion, dehydration, electrolyte imbalance including low calcium and magnesium levels.
Sometimes, circulation abnormalities to the hands or abnormal pressure over the nerves (like compression of median nerve at the wrists) can also present clinically in the form of painful muscle cramps and tingling.
So this clearly needs a clinical examination and if deemed necessary some blood work (such as calcium/magnesium levels) or nerve conduction studies will be require to ascertain the exact cause for this.
Right now you should have rest.
Gentle massage of the hands.
Drink lot of water and juices/gatorade.
And watchfully monitor your symptoms for next few hours/days.
If this does not improve or get worse, you should go to the doctor discussing all the details i have mentioned to get a management plan chalked out that suits best to your needs.
My goal is to provide you with Excellent Service - if satisfied with the response, Please do not forget to Rate my service as this is the only way i get credit for my time and expertise on your question.
If you feel you have gotten anything less, please reply back, I am happy to address follow-up questions.