Besides stress and panic disorders, neck numbness could be caused by a nerve or spinal disorder or compression, multiple sclerosis, whiplash or other injury, Guillain-Barre Syndrome, or arteriovenous malformation.
Numbness in the neck could be caused by a herniated disc in the neck. Injuries from whiplash could also cause numbness. Oftentimes when there is swelling, that causes nerves to be pinched off which will result in a numb feeling.
Any kind of numbness normally indicates a blockage or a pinching of a nerve. Considering that you feel this when you sit and the numbness is in your neck I would guess that something along your spinal cord is being pinched when you sit.
You could have been sitting for a long period of time and you're not getting enough blood flow to that area. You body is also protecting itself from getting injured.
Bulging discs in the neck or ruptured discs in the back can cause numbness and a stinging
sensation. Pressure being applied on the a nerve can make your neck feel numb and most likely
extend into your arms and hands.
A numb feeling in your neck while sitting can be due to carpal tunnel syndrome, poor posture while sitting for long periods of time, or a muscle wasting disorder. It may even be due to cancer.
Numbness in the neck is usually caused by a slipped or herniated disc, which irritates and damages vertebrae. This can get progressively worse until your whole back and legs get numb. Your doctor can give you a small electrode nerve stimulator to ease the pain, but serious surgery may be required. Consult at least 3 neurophysicians before deciding.
