Spinal Glossary: H

  • herniated disc: With age, the center of vertebral discs may start to lose water content, making the disc less effective as a cushion, causing displacement of the disc's center (herniated or ruptured disc) through a crack in the outer layer. Most disc herniations occur in the bottom two discs of the lumbar spine, at and just below the waist. A herniated disc can press on a nerve root in the spine and may cause back pain or pain, numbness, tingling or weakness of the leg called "sciatica." Also known as a slipped or ruptured disc, or herniated nucleus pulposus (HNP). Can also occur in the neck and, rarely, in the thoracic portion of the spine.
  • HHS (U.S. Department of Health and Human Services): The U.S. Government’s primary agency for protecting the health of Americans and providing essential human services. It is administered by a cabinet secretary who oversees 12 operating divisions, including the Food and Drug Administration, the National Institutes of Health and Centers for Disease Control and Prevention.
  • HMO (health maintenance organization): An organization that provides comprehensive health care to voluntarily enrolled people in a particular geographic area by member physicians with limited referral to outside specialists. An HMO is financed by fixed periodic payments determined in advance.
  • herniated nucleus pulposus (HNP): The leaking of the gel-like inner material (nucleus pulposus) of an intervertebral disc through a tear in the fibrous outer wall of the disc. This can occur as a result of the natural wear and tear of age, which causes the nucleus to lose water content and the wall to become brittle and weak. While not always symptomatic, contact by the extruded nucleus material with adjacent nerve roots or the spinal cord can produce pain, tingling, numbness or muscle weakness.
  • Hx (medical history): Medical shorthand for the background on a patient’s health. A physician may determine patient history through records or questioning the patient directly. This is also referred to as anamnesis.
  • HNP: Herniated nucleus pulposus (HNP) refers to a condition where a tear develops in the outer wall of an intervertebral disc causing the gel-like disc material – the nucleus pulposus – to extrude out of the disc into the spinal canal. HNP is also known as a herniated disc, ruptured disc and torn disc, among others.
  • hypertrophic: Descriptive term for an organ or body part that has experienced an enlargement of the cells. This is relevant to the spine in cases of ligamentum flavum hypertrophy, in which one or more of the ligaments between the vertebrae have begun to ossify, or thicken, potentially leading to nerve compression.