pain starts from the top of my shoulder...

Hi, welcome to the ehealth forum and I am glad to help you.
You seem concerned by the pain starting from the shoulder radiating down to the forearm, thumb and pinkey finger.
Pains that occur along the top of the shoulder, and radiate into the side of the upper arm into the deltoid muscle, and further down the arm, even into the fingers, may be related to nerve impingement (pinched nerve), which can originate in the neck (cervical spine). Depending on the side of the hand, or the fingers affected will determine the nerve branch involved.
This condition called “Brachial Neuritis”, or “Brachial Neuralgia”, is due to the involvement of the group of nerves exiting from the spinal vertebrae, called the “Brachial Plexus”. The pain can be very intense on any movement of the arm and any pressure along the distribution of the nerve pathway.
For the same reason it is essential that you consult your personal physician for the evaluation of the pain as the same is not possible online.
Hope this helps. Take care.
Note: This post is for patient education only and no specific diagnosis is claimed thereby.