Sciatica is pain that spreads down the path of the sciatic nerve, which runs from the lower back to the hips and buttocks and down each leg. Sciatica affects one side of your body.

Sciatica is most usually caused by a herniated disc, a bone spur on the spine, or a constriction of the spine (spinal stenosis). It thus causes inflammation, pain, and numbness in the afflicted limb.

Reasons for Sciatica Pain:

Sciatica is a frequent symptom of a variety of medical disorders; nevertheless, a herniated (slipped) disc is responsible for an estimated 90% of occurrences. The spinal column is divided into three sections:

  • Nerves
  • Disks
  • Vertebrae

The discs are formed of cartilage, a strong and vibrant substance that functions as a cushion between each vertebra and allows the spine to be flexible. When a disc is moved out of place, it puts pressure on the sciatic nerve.

  • Herniated Disks

Your vertebrae, or spinal bones, are connected by cartilage. Cartilage is packed with a thick, transparent substance that provides flexibility and cushioning as you move. Herniated discs happen when the initial layer of cartilage tears.

The material within might compress your sciatic nerve, causing discomfort and numbness in your lower limbs. It is anticipated that 1 to 5% of all people may experience back pain as a result of a slipped disc at some time in their lives.

According to research, a lumbar herniated disc can cause up to 90% of sciatica.  Typically, a herniated disc compresses one or more of the spinal nerve roots (L4-S3) that constitute the sciatic nerve. Sciatica can be caused by a lumbar herniated disc in two ways:

  1. Direct Compression: Direct compression of the sciatic nerve can occur when a lumbar disc bulges (contained disc condition) or when the soft inner material of the disc seeps out or herniates through the fibrous outer core and presses against the nerve (non-contained disc disorder).
  2. Chemical Inflammation: An acidic chemical irritant (hyaluronan) may leak out of the disc material and produce inflammation and pain in the sciatic nerve area.
  • Spinal stenosis

Spinal Stenosis is also called Lumbar Spinal Stenosis. It is distinguished by an abnormal narrowing of your lower spinal canal. This constriction exerts pressure on your spinal cord and the roots of your sciatic nerve.

A narrowing of the spinal column is referred to as spinal stenosis. The vertebrae will compress the spinal nerve as the column narrows. Pain, weakness, and numbness are among the symptoms. Spinal stenosis is frequently progressive and can cause leg discomfort. In more severe instances, bowel and bladder function may be impaired. Spinal stenosis is a degenerative condition that mainly affects people over the age of 60. Spinal stenosis can also be caused by herniated discs, spinal traumas, and hereditary disorders.

  • Spondylolisthesis

Spondylolisthesis is a disorder that mostly affects the lumbar spine. It occurs when one vertebra falls forward over an adjacent vertebra. When a vertebra slips and moves, it pushes on the nerves or nerve roots beneath it. This eventually leads to compression and, as a result, sciatica pain.

You either have developmental spondylolisthesis from birth or it develops during childhood. Acquired spondylolisthesis, on the other hand, can be caused by:

  1. Parts of the spine deterioration with time (spinal degeneration)
  2. Physical exertion from activities such as weightlifting or gymnastics
  3. Trauma
  • Piriformis syndrome

Piriformis syndrome is an uncommon neuromuscular illness in which your piriformis muscle contracts or tightens involuntarily, producing sciatica. The piriformis muscle links the lowest region of your spine to your thighbones.

It can put pressure on your sciatic nerve if it thickens, resulting in sciatica. Piriformis syndrome might worsen if you sit for lengthy periods of time, fall, or are involved in a vehicle accident.

Sciatica can be caused by the given factors as well:

  • Lumbar spinal stenosis is characterised by a narrowing of the spinal cord in the lower back.
  • Tumors in the spine — they can compress the sciatic nerve root.
  • Infection – eventually harming the spine
  • Other reasons, such as spine damage, may exist.
  • Cauda equina syndrome is an uncommon but dangerous disorder that affects nerves in the lower region of the spinal cord and needs rapid medical intervention.


Tissue degeneration in the lumbar spine can squeeze or irritate the sciatic nerve. Vertebral bone degeneration may result in irregular bone growths (bone spurs or osteophytes). These unusually thick tissues in the lumbar spine may induce compression of one or more sciatic nerve roots. Degenerated intervertebral discs may produce inflammatory proteins, producing sciatic nerve irritation.

Disc degeneration, often known as degenerative disc disease (DDD), is a frequent and almost unavoidable consequence of ageing. Intervertebral discs dry up over time—years and decades—a process known as disc desiccation. As the moisture content of the discs drops, they become weaker, more brittle, and more vulnerable to herniation.

Although DDD is extremely common and largely unavoidable, there are several lifestyle changes you may do to minimise your risk of or slow the progression of disc degeneration, such as:

  • Proper lifting mechanics must be practised.
  • Maintaining a healthy weight
  • Avoiding smoking and reducing alcohol consumption
  • Moving more and sitting less


Sciatica can be caused by a variety of problems that might pinch a sciatic nerve or nerve root. A patient may frequently “overdo” a slightly difficult job, such as gardening or lifting boxes. Limiting exercise, using ice to the lower back, and taking an over-the-counter anti-inflammatory medication will help the symptoms improve.

Sciatica is an extremely painful ailment. You might have severe pain but only experience it on rare occasions, or you could have less severe but regular sciatic discomfort.

Consult the experts of NeuroWellness if your symptoms do not improve with home therapy, if they persist for an extended period of time, or if you are having difficulties doing everyday duties. We can assist you in developing a treatment plan that is appropriate for you and we will try for you to get relieved from the pain as soon as possible.

Dr. Ganesh Veerabhadraiah is a leading Neurosurgeon and Interventional Neuroradiology Specialist at Fortis Hospital, Bengaluru. With over 23 years of experience, he's renowned for his expertise in brain and spine surgeries.Trained at prestigious institutions like Manipal Hospital and University Hospital Zurich, Dr. Ganesh is dedicated to providing cutting-edge neurological care. Read More :