Nerve related pain.
Thanks for posting your query.
The sudden appearance of acute pain with no history of injury
to the hand is likely to be due to a nerve related pain. This can happen due to a mild compression of the nerve root
at the level of cervical vertebra.
You need to consult a neurologist
for a detailed examination and to find out the exact site of lesion. Till then avoid using a pillow. You can also get pain killers and medicines like pregabalin
prescribed from your physician for relief.
I hope this answers your query.
In case you have additional questions or doubts, you can forward them to me, and I shall be glad to help you out.
Wishing you good health.
Dr. Praveen Tayal.
For future query, you can directly approach me through my profile URL http://bit.ly/Dr-Praveen-Tayal