Numbness and weakness in my hands while laying down to sleep. fine when in upright position. likely cause?

Multiple potential : Symptoms could be due to 1.Carpel tunnel syndrome . 2. Cervical root irritation 3.Cervical rib syndrome should see your md for evaluation.

Numbness both hands: A cervical cord lesion should be ruled out. Mri of the cervical spine will be recommended by the consulting physician. The possibility of a more distal pathology such as those involving the medial (carpal tunnel), radial and ulnar nerves is entertained. However, the latter condition behooves one to rule out a cervical cord lesion/myelopathy. Pe, MRI c/s, emg/ncv to start with. Good luck.