Hello, Thanks for your query. What your sister is experiencing is called Radiculopathy . It basically suggests entrapment of a nerve root in cervical spine in its origin or course. It is somehow not so uncommon now in younger population and we like to call it industrial neck pain, since its prediliction towards people working in computer related industry. It can be caused by lifting weights, episodes of over-exertion during work, long hours on computer, inappropriate posture while sleeping or sitting, lack of proper nutrition-exercises-rest-recreation or any other relevant past medical history. If it has been persistent or even increasing since few days, you need to visit your orthopaedician. Depending upon the clinical findings they might ask you to get an MRI done, which shall help establish a diagnosis and in turn allow one to formulate a treatment plan. I do hope that you have found something helpful and I will be glad to answer any further query. Take care