Persons most commonly affected: All age groups and both sexes.

Organ or part of body involved: Neck

Symptoms and indications: Stiff neck, neck swelling, neck lump and neck pain.

Causes and risk factors: Some of the causes of neck stiffness include: sleeping on a pillow the wrong way, a sudden turn of the neck, stress -- which can cause the neck muscles to tighten and become stiff, injury -- such as a whiplash as a result of a car accident, cervical arthritis -- an inflammatory condition affecting the upper spine and possibly other parts of the body, encephalitis -- a serious inflammation affecting the brain, meningitis -- a viral or bacterial infection affecting the membranes surrounding the spinal cord and brain, subarachnoid hemorrhage -- or bleeding into the space surrounding the brain, ankylosing spondylitis -- an inflammation and inability to move some of the upper vertebrae, often caused by arthritis, neck sprain -- which may be accompanied by pain, slight swelling, and restricted range of motion, rheumatoid arthritis, and torticollis -- a deformity of the neck caused by a shortening of the neck muscles. This condition causes the head to tilt to the affected side with the chin pointing to the other side.

Prevention: Some ways to prevent neck stiffness include the following: staying fit and exercising to keep the muscles of the neck stronger and more resistant to injury, avoiding exposure to someone who has meningitis, driving defensively to avoid motor vehicle accidents, following sports safety guidelines for children, adolescents, and adults, and seeking immediate medical care for a major injury, and using precautions when a person has been injured to decrease the likelihood of further injury.