Herniated Nucleus Pulposus (HNP) at L4/L5


If you are experiencing lower back pain or the condition known colloquially as sciatica, you may have a L4/L5 herniated nucleus pulposus (HNP) – or, more simply, a herniated disc between the fourth and fifth vertebrae in your lumbar spine. Also known as a ruptured or prolapsed disc, a disc herniation is a common type of degenerative spine condition that can sometimes be caused by an injury but is usually traced to the regular wear and tear on the spine that comes with aging. This condition can become painful when the herniated disc material – the nucleus pulposus – compresses the spinal cord, sciatic nerve or another nerve in the spinal column.

Spine degeneration

L4/L5 HNP is a degenerative spine condition that affects the intervertebral disc that cushions the two largest, strongest vertebrae in the spine. This disc is particularly susceptible to deterioration over time because the lumbar spine is the most flexible section of the spine and also supports the majority of the body’s weight. Over time, this mobility and weight burden take a toll and the disc can become worn out and rupture. When a tear develops in the fibrous wall of the disc, the nucleus pulposus can extrude into the spinal column. This condition isn’t necessarily symptomatic unless the nucleus pulposus causes nerve compression.

L4/L5 HNP can result in:

  • Sciatica
  • Chronic, lower back pain
  • Soreness or stiffness in the legs, knees, or hip joints
  • A burning sensation in the legs
  • Muscle weakness
  • Numbness or tingling

Treatment options

Treatment options vary depending on the severity and cause of L4/L5 HNP, but in most cases disc herniation is manageable with a series of conservative, non-surgical treatments, including heat therapy, pain medication and exercise. In the event that your pain persists through several weeks of treatment, contact Laser Spine Institute. We can tell you more about how one of our minimally invasive, outpatient procedures might be able to help you find relief from back pain.