Hello and thanks for posting,

There are many possible explanations for a stiff neck. Some immunotherapy drugs can cause joint aches and pains, so you could check this out with your hospital team first. Often though, it is related to poor posture, or sleeping using an unsupportive pillow. Using a memory foam type pillow can help. Arthritis type changes can also cause stiffness. You could ask your GP about it. They may suggest an x-ray, and a physiotherapy referral. 

There is some useful information about neck pain on the NHS website,

https://www.nhs.uk/conditions/neck-pain-and-stiff-neck/

I hope that this reply helps,

Please get back to us if you need any more information or support.  You may find it helpful to talk things through with one of the nurses on our helpline.  The number to call is Freephone 0808 800 4040 and the lines are open from 9am till 5pm Monday to Friday.

Yours sincerely,

Vanda