Neck pain is a common symptom that we often wake up in the morning with or experience at the end of a tiring day at work. It is usually a result of a minor strain or sprain and disappears with over-the-counter painkillers and symptomatic treatment at home. In some cases however, neck pain may be the result of a problem that requires emergency treatment.
The neck is made up of 7 bones called the cervical vertebrae, which constitute the spine in the neck region. The vertebrae protect the spinal cord. The vertebrae are stacked one on top of the other and kept in position by the anterior and posterior ligaments. Between the vertebrae are the intervertebral discs. The discs have a soft center surrounded by a tough fibrous part. The discs act as cushions and prevent friction during movement of the cervical vertebrae. Surrounding the vertebrae are various small as well as big muscles which support the spine and assist in movements.
Causes of neck pain may be located within the spine or in the ligaments or muscles surrounding the neck.
The parts of the neck that can perceive pain include the periosteum (the cover of the vertebrae), the outer ring of the intervertebral discs, the epidural veins (the veins located outside the covering of the spinal cord) and the posterior longitudinal ligament. Pain may also be caused due to pressure on a nerve. In such cases, the pain may be felt at a distant location along the area of distribution of the nerve. Such pain is called radicular pain.
The causes of neck pain are described below depending on the site of origin:
Pain from the Neck Muscles or Ligaments
Strain or sprain: Strain and sprain of the neck muscles are among the most common causes of neck pain. The muscles of the neck may undergo strain due to poor posture, poor sleeping habits or an injury to the muscles. Stress can also increase the muscle tension resulting in neck pain. Symptoms include pain, stiffness and tightness in the neck and sometimes upper back and shoulders. The pain may last for up to 6 weeks and is relieved with muscle relaxants and painkillers.
Whiplash injury: A whiplash injury is usually caused by trauma, often during a motor vehicle accident that causes an abrupt excessive forward / backward movement of the spine causing sprain of the ligaments. Symptoms include severe pain, spasm and reduced movement of the neck.
Diffuse skeletal hyperostosis: Diffuse skeletal hyperostosis is a condition where the muscles and ligaments in the neck show abnormal calcifications. Patients may develop stiffness, pain and loss of mobility. The lower spine may also be involved.
Pain from the Vertebrae
Fractures: Fractures of the vertebrae could occur due to trauma like motor vehicle accidents or falls. They could also be a result of diseases affecting the vertebrae like osteoporosis or thinning of the bone, cancer infiltration of the bone or the use of steroids. Fractures of the vertebrae can cause compression and damage to the spinal cord and require immediate immobilization of the neck.
Tumors of the vertebral column: Tumors affecting the vertebral column may be benign (like osteochondroma or osteoid osteoma) or malignant (like osteosarcoma or chondrosarcoma). In addition, cancer from other parts can also spread to the vertebral column. Pain due to tumors is of unrelenting type and present even at night. It is not relieved by rest or by usual treatments. Other symptoms include neck stiffness, decreased range of motion, weakness or numbness in case of compression of nerves and general symptoms like as low-grade fever, night sweats, fatigue, malaise, and loss of appetite.
Vertebral osteomyelitis: Osteomyelitis or infection of the vertebrae could occur due to spread from other sites via the blood or local spread from the throat, tonsils or the lower spine. Osteomyelitis is often caused by bacterial infection; in rare cases, it may be caused by tuberculosis or fungal infection. It is commonly seen in intravenous drug users. An abscess may also form, which could compress various structures resulting in neck pain. The infection could also spread to the intervertebral disc. Neck pain is increased by motion and is not relieved by rest. Pain is felt on pressing the affected vertebra. Fever, an increase in ESR and an increase in white blood cell count may be present. CT scan helps to confirm the diagnosis.
Metabolic: Metabolic or hormonal conditions can also result in neck pain. Conditions like osteoporosis or thinning of the bone, hyperparathyroidism or increased secretion of parathyroid hormone, or immobility can result in compression fractures. Osteosclerosis or increased bone density can occur due to Paget’s disease. Neck pain may be localized or spread along the compressed nerve. Pain is increased by movement and can be reproduced by pressure on the affected vertebra.
Cervical spondylotic myelopathy: Cervical spondylotic myelopathy is a condition that arises due to degenerative changes that narrow the spinal canal. This could result in compression of the spinal cord. Along with neck pain and decreased movement of the neck, other symptoms due to spinal cord compression could occur like muscle weakness, inability to empty bowel or bladder and sexual dysfunction.
Pain from the Vertebral Joints
Spondylosis: Spondylosis is a condition that results from abnormal wear and tear of the spinal column due to osteoarthritis. The discs get worn out, leading to narrowing of the space between the vertebrae. This results in friction during neck movements. Small growths called bone spurs arise at the joints that increase the friction and could press on nerves exiting the spinal cord. Thus, along with headache and neck pain, other symptoms due to pressure on nerves include muscle weakness and abnormal sensations of the arms and shoulders.
Facet arthropathy: The facets are small joints located at the sides of the vertebrae. Pain due to arthropathy of facets appears at the middle or the side of the neck, in the shoulders, upper back, base of the head or in one arm.
Rheumatoid arthritis and Ankylosing Spondylitis: Rheumatoid arthritis results in neck pain, stiffness and limitation of motion. In advanced cases, the upper cervical vertebrae may be displaced over each other leading to nerve-related symptoms. Ankylosing spondylitis may also cause neck pain and displacement of vertebrae.
Pain from the Intervertebral Disc
Herniation or prolapse of intervertebral disc: The intervertebral discs may be displaced from their position due to trauma or degeneration. They may press over the nerves coming out of the spinal cord, thus causing shoulder, arm or hand pain or tingling. Symptoms include neck pain, stiffness and decreased motion of the neck. Symptoms may be worse in certain positions that increase the compression.
Degenerative conditions: Degenerative conditions like disk osteophyte complex and internal disc disruption can result in neck pain. Disk osteophyte complex is a condition where the soft part of the disc herniates out along with an osteophyte or bone spur. It can cause pain when it impinges a nerve. Internal disc disruption is a condition where a tear develops in and bisects the intervertebral disc allowing the soft inner part of the disc to come in contact with the outer fibrous part, where the nerves are present.
Pain from the Meninges
Meningitis: Meningitis is a condition where the covering of the brain and spinal cord is inflamed. Along with neck pain, the patient experiences symptoms of fever, severe headache, neck stiffness, and sometimes seizures. Other symptoms include nausea, vomiting, dizziness sensitivity to light, rashes and weakness. Neck pain is increased with movement. The neck pain and stiffness may make it difficult for the patient to touch his chin to his chest.
Pain from Blood Vessels or Heart
Vertebral artery dissection: The vertebral arteries supply blood to the brain. Splitting of the vertebral artery wall is referred to as vertebral artery dissection. Symptoms include headache in the region just above the neck on the back of the head and neck pain following a minor head injury. Symptoms related to decrease in blood supply to the head may also appear, though these may be delayed by a few days after the onset of pain.
Angina: Pain from conditions that cause a decrease in blood supply to the heart like angina and heart attack can also result in neck pain. Other features related to the underlying condition like chest pain may also be present.
Pain from the Spinal Cord
Cancers of spinal cord: Along with neck and back pain, cancers of the spinal cord may also cause symptoms due to compression of nerves like weakness and pain at distant sites along the distribution of the nerves.
Chronic Pain Syndrome: Chronic pain syndrome is a condition where pain lasts for more than the expected duration. It is suggested to be a learned behavioral phenomenon: When the patient initially experiences pain, he is positively rewarded. This results in reinforcement of the pain, and the end consequence is that the pain is felt in the absence of the painful stimulus.
Fibromyalgia: Fibromyalgia is a condition where pain is felt at specific points on the body in the absence of underlying inflammation. Among other areas, it is also felt in the lower back part of the neck. The pain is felt even in the absence of a painful stimulus. Pain may be increased by stress, anxiety, activity and cold and damp weather. Associated symptoms include trouble sleeping, morning stiffness, headaches, and problems with thinking and memory.