Injuries and muscle tension are the most common causes of a stiff neck, according to Healthline. When a patient has poor posture, sleeps with his neck in an uncomfortable position or works at a desk for several hours without changing position, it can result in muscle strain in the neck. A neck injury resulting from a quick jerking of the head is also known as whiplash.
Several conditions and diseases, including arthritis, osteoporosis and spinal stenosis, can result in a stiff neck, reports Healthline. Arthritis usually leads to general neck pain, joint swelling and bone spurs. Chronic inflammation brought about by arthritis can also result in spinal stenosis, a condition that happens when the spinal column shrinks and adds pressure on the spinal cord. Osteoporosis is another condition that affects the bones, and it can cause fractures as well.
A stiff neck can also be due to emotional stress, according to Everyday Health. Patients going through a lot of stress usually have tense muscles that cause neck stiffness. A disorder called fibromyalgia is also known to cause painful joints and muscles. When nerves send signals that make muscles contract, it can lead to muscle spasms and neck stiffness. A patient with a pinched nerve due to a narrowing spinal canal, a herniated disk or arthritis can experience a stiff neck that extends to his arms and legs.