Intervertebral Disc Degeneration

Intervertebral disc degeneration is a common condition where the cushioning discs in your spine break down over time, potentially causing back or neck pain that can interfere with daily activities. While almost everyone experiences some disc wear as they age, not everyone develops symptoms, and effective management strategies can help you maintain an active, comfortable life.

Table of contents

• What is Intervertebral Disc Degeneration?
• Associated Anatomy
• Causes and Risk Factors
• Signs and Symptoms
• How Common Is This Condition?
• Diagnosis
• Treatment Options
• Living with Disc Degeneration
• Prevention and Lifestyle Changes

What is Intervertebral Disc Degeneration?

Intervertebral disc degeneration is a common condition characterized by the breakdown of one or more of the discs that separate the bones of the spine, causing pain in the back or neck and frequently in the legs and arms^[2]. Despite its name, degenerative disc disease isn’t actually a disease, but rather a condition that occurs when your spinal disks wear down^[1].

The spinal discs are rubbery cushions between your vertebrae (bones in your spinal column). They act as shock absorbers and help you move, bend and twist comfortably^[1]. The intervertebral discs provide cushioning between vertebrae and absorb pressure put on the spine^[2].

The process of disc degeneration is an aberrant, cell-mediated response to progressive structural failure. A degenerate disc is one with structural failure combined with accelerated or advanced signs of aging^[3].

Everyone’s spinal disks degenerate over time — it’s a natural part of aging. When the cushions wear away, the bones can start to rub together. This contact can cause pain and other problems^[1].

Associated Anatomy

• Spinal discs (intervertebral discs)
• Vertebrae
• Lumbar spine (lower back)
• Cervical spine (neck)
• Thoracic spine (upper back)
• Spinal nerves
• Facet joints

Each disc has two parts: a firm, tough outer layer called the anulus fibrosus, and a soft, jellylike core called the nucleus pulposus. The outer portion contains nerves, so if the disc tears in this area, it can become quite painful. The core contains proteins that can cause the tissues they touch to become swollen and tender^[4].

Disc degeneration mostly affects your lower back (lumbar spine) or neck (cervical spine). Your lower back has five vertebrae, which healthcare providers call L1 to L5. Approximately 90% of degenerative disk disease occurs in the lowest portions of your lumbar spine^[1].

While the discs in the lower (lumbar) region of the spine are most often affected in intervertebral disc disease, any part of the spine can have disc degeneration^[2].

Causes and Risk Factors

Intervertebral disc degeneration results from a combination of genetic and environmental factors^[2]. Spinal disks wear down as a natural part of aging. Especially after age 40, most people experience some disk degeneration^[1].

Genetic Factors

Researchers have identified variations in several genes that may influence the risk of developing intervertebral disc disease. The most commonly associated genes provide instructions for producing proteins called collagens. Collagens are a family of proteins that strengthen and support connective tissues, such as skin, bone, cartilage, tendons, and ligaments^[2].

Specific variations in several collagen genes seem to affect the risk of developing intervertebral disc disease by impairing the ability of collagens to interact with each other, decreasing the stability of the disc and leading to its degeneration^[2].

Normal variations in genes related to the body’s immune function are also associated with an increased risk of developing intervertebral disc disease. It is thought that these gene variants can lead to an immune response that results in inflammation and water loss (dehydration) of the discs, which causes their degeneration^[2].

degenerative disc disease, DDD, degenerative disk disease, disc degeneration

How Discs Degenerate

You might have pain if your spinal disks dry out or tear. Your disks have a soft core that mostly contains water. As you get older, that core naturally loses some water. As a result, disks get thinner and don’t provide as much shock absorption as they used to^[1].

Minor injuries can lead to small cracks in your spinal disks. These tears are often near nerves. Tears can initiate inflammation^[1]. Unlike other tissues of the body, the disc has very low blood supply. Once a disc is injured, it cannot repair itself, and a spiral of degeneration can set in^[4].

Risk Factors

Nongenetic factors that contribute to the risk of intervertebral disc disease include^[2]:

• Aging
• Smoking
• Obesity
• Chronic inflammation
• Driving for long periods of time

Environmental factors such as smoking, along with concurrent health problems like diabetes and obesity have also been associated with degenerative disc disease. Additionally, it has been shown that low estrogen levels, such as that in postmenopausal females, may also impact the integrity of intervertebral discs^[7].

Daily activities and sports can cause tears in the outer core of the disc. By age 60, most people have some degree of disc degeneration^[4].

Signs and Symptoms

The most common degenerative disk disease symptoms are neck pain and back pain. You may experience pain that comes and goes, lasting for weeks or months at a time, radiates down your lower back and buttocks, and worsens with sitting, bending or lifting^[1].

Degenerative disk pain can happen in your neck or lower back, can be mild, moderate or severe, can be sharp, aching or stiff, may start and stop, can get worse after certain activities like bending, twisting or lifting, and can get worse over time^[1].

Depending on the location of the affected disc or discs, intervertebral disc disease can cause periodic or chronic pain in the back or neck. Pain is often worse when sitting, bending, twisting, or lifting objects^[2].

The typical person with degenerative disc disease is active, otherwise healthy and in his or her 30s or 40s. Common symptoms of this condition include pain that is worse when sitting, pain that gets worse when bending, lifting or twisting, and feeling better while walking or even running than while sitting or standing for long periods of time^[4].

Additional Symptoms

Degenerated discs are prone to out-pouching (herniation); the protruding disc can press against one of the spinal nerves that run from the spinal cord to the rest of the body. This pressure causes pain, weakness, and numbness in the back and legs^[2].

Herniated discs often cause nerve pain called sciatica that travels along the sciatic nerve, which runs from the lower back down the length of each leg^[2].

As a disc degenerates, small bony outgrowths (bone spurs) may form at the edges of the affected vertebrae. These bone spurs may pinch (compress) the spinal nerves, leading to weakness or numbness in the arms or legs. If the bone spurs compress the spinal cord, affected individuals can develop problems with walking and bladder and bowel control^[2].

Over time, a degenerating disc may break down completely and leave no space between vertebrae, which can result in impaired movement, pain, and nerve damage^[2].

How Common Is This Condition?

Intervertebral disc disease is estimated to affect about 5 percent of the population in developed countries each year. Most individuals experience disc degeneration as they age; however, the severity of the degeneration and the pain associated with it varies^[2].

Almost everyone has some disk degeneration after age 40, even if they don’t develop symptoms. It can lead to back pain in about 5% of adults^[1].

It’s estimated that up to 30% of people aged 30-50 may have some degree of disc degeneration, although not everyone experiences symptoms. About 40% of people aged 40 and 80% of those aged 80 show evidence of degenerative disc disease in X-rays or other radiological tests^[21].

Diagnosis

Diagnosing degenerative disc disease is a multi-step process often involving medical history evaluation, physical examination, and imaging tests^[21].

A thorough medical history is typically the first step, where healthcare providers will ask questions related to your pain, its duration, and any potential triggers. They’ll also want to know about specific symptoms, like if pain is localized in lower back or radiating into the legs^[21].

Imaging tests may be used to confirm the diagnosis and assess the extent of degeneration. These tests can include X-rays, CT scans, or MRI scans that show the structure of the spine and discs.

Treatment Options

Treatment for painful degenerative disc disease focuses on minimizing pain, stabilizing the spine, and improving or maintaining mobility^[14]. Degenerative disc disease can usually be treated with a combination of pain management techniques, physical therapy, and other approaches^[14].

Conservative Treatment

Initial pain management methods for degenerative disc pain typically include a combination of over-the-counter (OTC) pain medications, prescription pain medications for severe pain, heat and ice application, manual manipulation, massage therapy, and epidural steroid injections^[14].

NSAIDs (nonsteroidal anti-inflammatory drugs) like aspirin, ibuprofen, or naproxen are common pain medications that can relieve inflammation that contributes to discomfort, stiffness, and nerve root irritation. Acetaminophen is a pain reliever that interferes with pain signals sent to the brain^[14].

Applying heat to the low back improves circulation, which reduces muscle spasms and tension and improves mobility. Ice packs can reduce inflammation and numb mild pain^[14].

Physical Therapy

Physical therapy is often suggested or prescribed to help maintain healthy mobility in the spine. A physical therapist can design a personalized exercise program to strengthen the core and back muscles, improve flexibility, and reduce strain on the spine^[13]. Gentle stretches, low-impact aerobic exercises, and posture correction are particularly beneficial for minimizing discomfort and maintaining spinal health^[13].

Advanced and Biological Therapies

When conservative measures fail to provide adequate relief, more advanced treatments may be considered^[7].

Biologic treatment options are an alternative to conventional management and have become very attractive in recent years. Biologic treatment options include protein-based and cell-based therapies^[12].

Protein-based therapies involve administration of biologic factors into the intervertebral disc to enhance matrix synthesis, delay degeneration or impede inflammation. These factors can be delivered by an intradiscal injection, alone or in combination with cells or tissue scaffolds and by gene therapy^[12].

Cell-based therapies comprise treatment strategies that aim to either replace necrotic or apoptotic cells, or minimize cell death. Cell-based therapies are more appropriate in moderate stages of degenerated disc disease, when cell population is diminished^[12].

Although clinical application of biologic treatments is far from being an everyday practice, the existing studies demonstrate promising results^[12].

Surgical Options

In severe cases which have not responded to non-operative management, surgery may be considered^[7]. Surgical interventions are typically reserved for patients whose symptoms significantly impact their quality of life and have not improved with conservative treatment.

Living with Disc Degeneration

Many individuals with a degenerated disc can live a normal and fulfilling life by adopting the right treatment strategies and lifestyle modifications^[15].

Staying active with low-impact exercises like walking, swimming, or yoga can help maintain mobility, improve circulation, and reduce pain. Regular activity also promotes the release of endorphins, which act as natural painkillers, boosting mood and overall well-being^[15].

Proper posture is equally important in reducing strain on the spine. Whether sitting, standing, or lifting objects, keeping the spine in a neutral alignment can help prevent worsening of symptoms. For individuals who spend long hours sitting, investing in an ergonomic chair and taking regular breaks to stretch can provide significant relief^[13].

Contrary to popular belief, rest alone is not the best approach for managing a degenerated disc. Prolonged inactivity can lead to muscle stiffness and weakness, which may worsen symptoms over time^[15].

Prevention and Lifestyle Changes

While complete prevention isn’t possible because some degree of degeneration naturally occurs with aging, you can take meaningful steps to slow the process and minimize symptoms^[20].

Weight Management

Maintaining a healthy weight is crucial, as excess weight places additional pressure on the spine, exacerbating symptoms^[13]. Obesity is a risk factor that puts severe strain on the spine, increasing the risk of disc degeneration^[19].

Nutrition

A balanced diet rich in calcium, vitamin D, and anti-inflammatory foods can promote bone and disc health, further supporting spinal integrity^[13]. Fighting inflammation is key when suffering from degenerative disc disease, and diet can play a role in managing this symptom^[16].

Foods that may benefit spinal health include colorful fruits and vegetables, fatty fish (salmon, mackerel), nuts and seeds, olive oil, and turmeric and ginger^[14].

Avoiding Risk Factors

Smoking reduces blood flow and can affect the ability to heal, which can contribute to disc degeneration. The rate of disc degeneration in smokers is four times faster than a nonsmoker^[19].

You may need to avoid certain activities that can worsen symptoms, such as heavy lifting, high-impact exercise and sports, and prolonged sitting^[19].

Core Strength and Flexibility

Poor core strength and flexibility can make the spine subject to injury and degeneration^[19]. Appropriate exercises, like strength training and lifting, can help preserve and stabilize the spine, back, and core muscles. Walking, swimming, cycling, gentle stretching, and core-strength exercises all help reduce pressure on compromised discs^[20].