Most people with mild to moderate symptoms do not get worse. While many improve in the short term after surgery this improvement decreases somewhat with time. A number of factors present before surgery are able to predict the outcome after surgery, with people with depression, cardiovascular disease and scoliosis doing in general worse while those with more severe stenosis beforehand and better overall health doing better.

The natural evolution of disc disease and degeneration leads to stiffening of the intervertebral joint. This leads to osteophyte formation—a bony overgrowth about the joint. This process is called spondylosis, and is part of the normal aging of the spine. This has been seen in studies of normal and diseased spines. Degenerative changes begin to occur without symptoms as early as age 25–30 years. It is not uncommon for people to experience at least one severe case of low back pain by the age of 35 years. This can be expected to improve and become less prevalent as the individual develops osteophyte formation around the discs.

In the US workers' compensation system, once the threshold of two major spinal surgeries is reached, the vast majority of workers will never return to any form of gainful employment. Beyond two spinal surgeries, any more are likely to make the patient worse, not better.

Surgery may be useful in those with a herniated disc that is causing significant pain radiating into the leg, significant leg weakness, bladder problems, or loss of bowel control. Discectomy (the partial removal of a disc that is causing leg pain) can provide pain relief sooner than nonsurgical treatments. Discectomy has better outcomes at one year but not at four to ten years. The less invasive microdiscectomy has not been shown to result in a significantly different outcome than regular discectomy with respect to pain. It might however have less risk of infection.

The presence of cauda equina syndrome (in which there is incontinence, weakness and genital numbness) is considered a medical emergency requiring immediate attention and possibly surgical decompression. Regarding the role of surgery for failed medical therapy in people without a significant neurological deficit, a Cochrane review concluded that "limited evidence is now available to support some aspects of surgical practice".

Disc herniation can occur in any disc in the spine, but the two most common forms are lumbar disc herniation and cervical disc herniation. The former is the most common, causing lower back pain (lumbago) and often leg pain as well, in which case it is commonly referred to as sciatica. Lumbar disc herniation occurs 15 times more often than cervical (neck) disc herniation, and it is one of the most common causes of lower back pain. The cervical discs are affected 8% of the time and the upper-to-mid-back (thoracic) discs only 1–2% of the time.

The following locations have no discs and are therefore exempt from the risk of disc herniation: the upper two cervical intervertebral spaces, the sacrum, and the coccyx. Most disc herniations occur when a person is in their thirties or forties when the nucleus pulposus is still a gelatin-like substance. With age the nucleus pulposus changes ("dries out") and the risk of herniation is greatly reduced. After age 50 or 60, osteoarthritic degeneration (spondylosis) or spinal stenosis are more likely causes of low back pain or leg pain.

- 4.8% males and 2.5% females older than 35 experience sciatica during their lifetime.

- Of all individuals, 60% to 80% experience back pain during their lifetime.

- In 14%, pain lasts more than 2 weeks.

- Generally, males have a slightly higher incidence than females.

Generally, there are two forms of syringomyelia: congenital and acquired. (In addition, one form of the disorder involves the brainstem. The brainstem controls many of our vital functions, such as respiration and heartbeat. When syrinxes affect the brainstem, the condition is called syringobulbia.)

The first major form relates to an abnormality of the brain called an Arnold–Chiari malformation or Chiari Malformation. This is the most common cause of syringomyelia, where the anatomic abnormality, which may be due to a small posterior fossa, causes the lower part of the cerebellum to protrude from its normal location in the back of the head into the cervical or neck portion of the spinal canal. A syrinx may then develop in the cervical region of the spinal cord. Here, symptoms usually begin between the ages of 25 and 40 and may worsen with straining, called a valsalva maneuver, or any activity that causes cerebrospinal fluid pressure to fluctuate suddenly. Some patients, however, may have long periods of stability. Some patients with this form of the disorder also have hydrocephalus, in which cerebrospinal fluid accumulates in the skull, or a condition called arachnoiditis, in which a covering of the spinal cord—the arachnoid membrane—is inflamed.

Some cases of syringomyelia are familial, although this is rare.

No set risk factors have been clearly defined for CES at this point in time. Individuals most at risk for disc herniation are the most likely to develop CES. Race has little influence with the notable exception that African Americans appear slightly less likely to develop CES than other groups; similarly, men are slightly more likely to develop CES than women. Middle age also appears to be a notable risk factor, as those populations are more likely to develop a herniated disc; heavy lifting can also be inferred as a risk factor for CES.

CES is often concurrent with congenital or degenerative diseases and represents a high cost of care to those admitted to the hospital for surgery. Hospital stays generally last 4 to 5 days, and cost an average of $100,000 to $150,000, unless the patient lives in a country where healthcare is free at the point of delivery.

Arachnoiditis is a chronic disorder with no known cure, and prognosis may be hard to determine because of an unclear correlation between the beginning of the disease and the appearance of symptoms. For many, arachnoiditis is a disabling disease that causes chronic pain and neurological deficits, and may also lead to other spinal cord conditions, such as syringomyelia.

The root cause of the condition is not entirely clear, and it appears to have multiple causes, including iatrogenic cause from misplaced epidural steroid injection therapy when accidentally administered intrathecally (inside the dura mater, the sac enveloping the arachnoid mater), or from contrast media used in myelography prior to the introduction of Metrizamide. Other noninfectious inflammatory processes include surgery, intrathecal hemorrhage, and the administration of anesthetics (e.g. chloroprocaine), and steroids (e.g. prednisolone, triamcinolone acetonide). A variety of other causes exist, including infectious, inflammatory, and neoplastic processes. Infectious causes include bacterial, viral, fungal, and parasitic agents. Prior spinal surgery has been documented as a cause of "arachnoiditis ossificans", as well as for the adhesive form. It can also be caused by long term pressure from either a severe disc herniation or spinal stenosis.

Tethered spinal cord can be caused by various conditions but the main cause is when tissue attachments limit the movement of the spinal cord in the spinal column which causes abnormal stretching of the cord. The tethered spinal cord syndrome is correlated with having the causes:

- Spina bifida

- Occulta

- Mylomeningocele

- Meningocele

- History of spinal trauma

- History of spinal surgery

- Tumor(s) in the spinal column

- Thickened and/or tight filum terminale

- Lipoma(s) in the spinal column

- Dermal Sinus Tract (congenital deformity)

- Diastematomyelia (split spinal cord)

Tethered spinal cord is a disorder and not a mechanism so it does not spread to other people and there are no measures that can be done to prevent it beforehand. The only preventative measure that is successful is to surgically untether the spinal cord though there might already be irreversible damage.

Because neurological deficits are generally irreversible, early surgery is recommended when symptoms begin to worsen. In children, early surgery is recommended to prevent further neurological deterioration, including but not limited to chronic urinary incontinence.

In adults, surgery to detether (free) the spinal cord can reduce the size and further development of cysts in the cord and may restore some function or alleviate other symptoms. Although detethering is the common surgical approach to TCS, another surgical option for adults is a spine-shortening vertebral osteotomy. A vertebral osteotomy aims to indirectly relieve the excess tension on the spinal cord by removing a portion of the spine, shortening it. This procedure offers a unique benefit in that the spinal cord remains fixated to the spine, preventing retethering and spinal cord injury as possible surgical complications. However, its complexity and limited “track record” presently keeps vertebral osteotomies reserved as an option for patients who have failed in preventing retethering after detethering procedure(s).

Other treatment is symptomatic and supportive. Medications such as NSAIDs, opiates, synthetic opiates, COX-2 inhibitors, and off-label applications of tricyclic antidepressants combined with anti-seizure compounds have yet to prove they are of value in treatment of this affliction's pain manifestations. There is anecdotal evidence that TENS units may benefit some patients.

Treatment may be needed in adults who, while previously asymptomatic, begin to experience pain, lower back degeneration, scoliosis, neck and upper back problems and bladder control issues. Surgery on adults with minimal symptoms is somewhat controversial. For example, a website from the Columbia University Department of Neurosurgery says, "For the child that has reached adult height with minimal if any symptoms, some neurosurgeons would advocate careful observation only." However, surgery for those who have worsening symptoms is less controversial. If the only abnormality is a thickened, shortened filum, then a limited lumbosacral laminectomy with division of the filum may be sufficient to relieve the symptoms.

This syndrome was first noticed in the late 19th century. While information has been available for years, little widespread blind research has been done. More research has been called for, and doctors have conducted many studies with good results. There is a low morbidity rate, and no complications have been documented other than those typical of any type of back surgery. The association of this condition with others has been noticed, and needs further research to understand such relationships. TCS is causally linked to Chiari malformation and any affirmative diagnosis of TCS must be followed by screening for Chiari's several degrees. TCS may also be related to Ehlers-Danlos syndrome, or Klippel-Feil syndrome, which should also be screened for upon a positive TCS diagnosis. Spinal compression and the resulting relief is a known issue with this disorder. Like with the early-onset form, this disease form is linked to the Arnold-Chiari malformation, in which the brain is pulled or lowers into the top of the spine.

Vehicle-related SCI is prevented with measures including societal and individual efforts to reduce driving under the influence of drugs or alcohol, distracted driving, and drowsy driving. Other efforts include increasing road safety (such as marking hazards and adding lighting) and vehicle safety, both to prevent accidents (such as routine maintenance and antilock brakes) and to mitigate the damage of crashes (such as head restraints, air bags, seat belts, and child safety seats). Falls can be prevented by making changes to the environment, such as nonslip materials and grab bars in bathtubs and showers, railings for stairs, child and safety gates for windows. Gun-related injuries can be prevented with conflict resolution training, gun safety education campaigns, and changes to the technology of guns (such as trigger locks) to improve their safety. Sports injuries can be prevented with changes to sports rules and equipment to increase safety, and education campaigns to reduce risky practices such as diving into water of unknown depth or head-first tackling in association football.

Lumbar spinal stenosis (LSS) is a medical condition in which the spinal canal narrows and compresses the nerves at the level of the lumbar vertebrae. This is usually due to the common occurrence of spinal degeneration that occurs with aging. It can also sometimes be caused by spinal disc herniation, osteoporosis, a tumor, or trauma. In the cervical (neck) and lumbar (low back) region it can be a congenital condition to varying degrees.

It is also a common symptom for those who suffer from various skeletal dysplasias such as with pseudoachondroplasia and achondroplasia at an early age.

Spinal stenosis may affect the cervical or thoracic region in which case it is known as cervical spinal stenosis or thoracic spinal stenosis. In some cases, it may be present in all three places in the same patient. Lumbar spinal stenosis can cause low back pain, abnormal sensations, and the absence of sensation (numbness) in the legs, thighs, feet or buttocks, or loss of bladder and bowel control.

The most common forms are cervical spinal stenosis, which are at the level of the neck, and lumbar spinal stenosis, at the level of the lower back. Thoracic spinal stenosis, at the level of the mid-back, is much less common.

In lumbar stenosis, the spinal nerve roots in the lower back are compressed which can lead to symptoms of sciatica (tingling, weakness, or numbness that radiates from the low back and into the buttocks and legs).

Cervical spinal stenosis can be far more dangerous by compressing the spinal cord. Cervical canal stenosis may lead to myelopathy, a serious conditions causing symptoms including major body weakness and paralysis. Such severe spinal stenosis symptoms are virtually absent in lumbar stenosis, however, as the spinal cord terminates at the top end of the adult lumbar spine, with only nerve roots (cauda equina) continuing further down. Cervical spinal stenosis is a condition involving narrowing of the spinal canal at the level of the neck. It is frequently due to chronic degeneration, but may also be congenital or traumatic. Treatment frequently is surgical.

There are many recognized spinal diseases, some more common than others. Spinal disease also includes cervical spine diseases, which are diseases in the vertebrae of the neck. A lot of flexibility exists within the cervical spine and because of that, it is common for an individual to damage that area, especially over a long period of time. Some of the common cervical spine diseases include degenerative disc disease, cervical stenosis, and cervical disc herniation. Degenerative disc disease occurs over time when the discs within each vertebra in the neck begin to fall apart and begin to disintegrate. Because each vertebra can cause pain in different areas of the body, the pain from the disease can be sensed in the back, leg, neck area, or even the arms. When the spinal canal begins to lose its gap and gets thinner, it can cause pain in the neck, which can also cause a numb feeling in the arms and hands. Those are symptoms of cervical stenosis disease. The discs between each vertebra have fibers that can begin to deteriorate, and this can occur in cervical disc herniation. This disease is less common in younger people as it is usually a function of aging.

Spinal cord injuries are most often caused by physical trauma. Forces involved can be hyperflexion (forward movement of the head); hyperextension (backward movement); lateral stress (sideways movement); rotation (twisting of the head); compression (force along the axis of the spine downward from the head or upward from the pelvis); or distraction (pulling apart of the vertebrae). Traumatic SCI can result in contusion, compression, or stretch injury. It is a major risk of many types of vertebral fracture. Pre-existing asymptomatic congenital anomalies can cause major neurological deficits, such as hemiparesis, to result from otherwise minor trauma.

In the US, Motor vehicle accidents are the most common cause of SCIs; second are falls, then violence such as gunshot wounds, then sports injuries. In some countries falls are more common, even surpassing vehicle crashes as the leading cause of SCI. The rates of violence-related SCI depend heavily on place and time. Of all sports-related SCIs, shallow water dives are the most common cause; winter sports and water sports have been increasing as causes while association football and trampoline injuries have been declining. Hanging can cause injury to the cervical spine, as may occur in attempted suicide. Military conflicts are another cause, and when they occur they are associated with increased rates of SCI. Another potential cause of SCI is iatrogenic injury, caused by an improperly done medical procedure such as an injection into the spinal column.

SCI can also be of a nontraumatic origin. Nontraumatic lesions cause anywhere from 30 to 80% of all SCI; the percentage varies by locale, influenced by efforts to prevent trauma. Developed countries have higher percentages of SCI due to degenerative conditions and tumors than developing countries. In developed countries, the most common cause of nontraumatic SCI is degenerative diseases, followed by tumors; in many developing countries the leading cause is infection such as HIV and tuberculosis. SCI may occur in intervertebral disc disease, and spinal cord vascular disease. Spontaneous bleeding can occur within or outside of the protective membranes that line the cord, and intervertebral disks can herniate. Damage can result from dysfunction of the blood vessels, as in arteriovenous malformation, or when a blood clot becomes lodged in a blood vessel and cuts off blood supply to the cord. When systemic blood pressure drops, blood flow to the spinal cord may be reduced, potentially causing a loss of sensation and voluntary movement in the areas supplied by the affected level of the spinal cord. Congenital conditions and tumors that compress the cord can also cause SCI, as can vertebral spondylosis and ischemia. Multiple sclerosis is a disease that can damage the spinal cord, as can infectious or inflammatory conditions such as tuberculosis, herpes zoster or herpes simplex, meningitis, myelitis, and syphilis.

Basilar invagination can be present at birth. If the condition develops after birth, it is usually the result of injury or diseases. If due to injury, about half the time it is caused by vehicle or bicycle accidents; 25% of the time by falls and 10% of the time by recreational activities such as diving accidents.

It also occurs in patients with bone diseases, such as osteomalacia, rheumatoid arthritis, Paget's disease, Ehlers-Danlos syndrome, Marfan syndrome, and osteogenesis imperfecta.

Spinal disease (also known as a dorsopathy) refers to a condition impairing the backbone. These include various diseases of the back or spine ("dorso-"), such as kyphosis. Dorsalgia refers to those conditions causing back pain.

An example is scoliosis. Some other spinal diseases include Spinal Muscular Atrophy, Ankylosing Spondylitis, Lumbar Spinal Stenosis, Spina Bifida, Spinal tumors, Osteoporosis and Cauda Equina Syndrome.

Due to extensive physical contact and activity, many athletes become victim to myelomalacia. Any accidents or injuries attained during athletic competition to the spinal cord may result in myelomalacia. Accounts of awkward landing on the ground or being hit intensively have attested to spinal cord injury.

The most common way the disorder occurs is from a result of hemorrhaging (bleeding within) or inadequate blood supply to the spinal cord, making it weak and susceptible to damage.

Because myelomalacia involves a damaged spinal cord, it may occur in any individual. Those most at risk are the geriatric population due to weaker bone density. Once the spinal injury has occurred, one of two things may happen. Firstly, hemorrhaging within the spinal cord may cause compression, which damages the spinal cord even further. Another consequence of myelomalacia is improper circulation of blood to the area damaged, resulting in further damage to the spinal cord.

Spinal stenosis is an abnormal narrowing of the spinal canal or neural foramen that results in pressure on the spinal cord or nerve roots. Symptoms may include pain, numbness, or weakness in the arms or legs. Symptoms are typically gradual in onset and improve with bending forwards. Severe symptoms may include loss of bladder control, loss of bowel control, or sexual dysfunction.

Causes may include osteoarthritis, rheumatoid arthritis, spinal tumors, trauma, Paget's disease of the bone, scoliosis, spondylolisthesis, and the genetic condition achondroplasia. It can be classified by the part of the spine affected into cervical, thoracic, and lumbar stenosis. Lumbar stenosis is the most common followed by cervical stenosis. Diagnosis is generally based on symptoms and medical imaging.

Treatment may involve medications, bracing, or surgery. Medications may include NSAIDs, acetaminophen, or steroid injections. Stretching and strengthening exercises may also be useful. Limiting certain activities may be recommended. Surgery is typically only done if other treatments are not affected, with the usual procedure being a decompressive laminectomy.

Spinal stenosis occurs in as many as 8% of people. It occurs most commonly in people over the age of 50. Males and females are affected equally commonly. The first modern description of the condition is from 1803 by Antoine Portal. Evidence of the condition, however, dates back to Ancient Egypt.

Cervical spinal stenosis is a bone disease involving the narrowing of the spinal canal at the level of the neck. It is frequently due to chronic degeneration, but may also be congenital. Treatment is frequently surgical.

Cervical spinal stenosis is one of the most common forms of spinal stenosis, along with lumbar spinal stenosis (which occurs at the level of the lower back instead of in the neck). Thoracic spinal stenosis, at the level of the mid-back, is much less common. Cervical spinal stenosis can be far more dangerous by compressing the spinal cord. Cervical canal stenosis may lead to serious symptoms such as major body weakness and paralysis. Such severe spinal stenosis symptoms are virtually absent in lumbar stenosis, however, as the spinal cord terminates at the top end of the adult lumbar spine, with only nerve roots (cauda equina) continuing further down. Cervical spinal stenosis is a condition involving narrowing of the spinal canal at the level of the neck. It is frequently due to chronic degeneration, but may also be congenital or traumatic. Treatment frequently is surgical.

Diastematomyelia (occasionally diastomyelia) is a congenital disorder in which a part of the spinal cord is split, usually at the level of the upper lumbar vertebra.

Diastematomyelia is a rare congenital anomaly that results in the "splitting" of the spinal cord in a longitudinal (sagittal) direction. Females are affected much more commonly than males. This condition occurs in the presence of an osseous (bone), cartilaginous or fibrous septum in the central portion of the spinal canal which then produces a complete or incomplete sagittal division of the spinal cord into two hemicords. When the split does not reunite distally to the spur, the condition is referred to as a diplomyelia, or true duplication of the spinal cord.

Dexamethasone (a potent glucocorticoid) in doses of 16 mg/day may reduce edema around the lesion and protect the cord from injury. It may be given orally or intravenously for this indication.

Surgery is indicated in localised compression as long as there is some hope of regaining function. It is also occasionally indicated in patients with little hope of regaining function but with uncontrolled pain. Postoperative radiation is delivered within 2–3 weeks of surgical decompression. Emergency radiation therapy (usually 20 Gray in 5 fractions, 30 Gray in 10 fractions or 8 Gray in 1 fraction) is the mainstay of treatment for malignant spinal cord compression. It is very effective as pain control and local disease control. Some tumours are highly sensitive to chemotherapy (e.g. lymphomas, small-cell lung cancer) and may be treated with chemotherapy alone.

Once complete paralysis has been present for more than about 24 hours before treatment, the chances of useful recovery are greatly diminished, although slow recovery, sometimes months after radiotherapy, is well recognised.

The median survival of patients with metastatic spinal cord compression is about 12 weeks, reflecting the generally advanced nature of the underlying malignant disease.

The treatment and prognosis of myelopathy depends on the underlying cause: myelopathy caused by infection requires medical treatment with pathogen specific antibiotics. Similarly, specific treatments exist for multiple sclerosis, which may also present with myelopathy. As outlined above, the most common form of myelopathy is secondary to degeneration of the cervical spine. Newer findings have challenged the existing controversy with respect to surgery for cervical spondylotic myelopathy by demonstrating that patients benefit from surgery.