Schmorl’s Node
A Schmorl’s node is a small protrusion of disc material into the spongy bone of an adjacent vertebra, occurring through a defect in the vertebral endplate. Schmorl’s nodes are extremely common and most often discovered incidentally on imaging performed for other reasons. The vast majority cause no symptoms, but a small number, particularly when they are new or actively forming, can produce localized back pain. They are most frequently found in the thoracic and upper lumbar spine.
What is it?
A Schmorl’s node is a small herniation of intervertebral disc material vertically into the body of an adjacent vertebra, through a defect in the bony endplate. The endplates are the thin layers of bone that separate each disc from the vertebra above and below. When the endplate has a weak area, the soft inner part of the disc can press through it and create a small, well-defined indentation within the vertebral body. These lesions were first described by German pathologist Christian Schmorl, which is how they got their name.
Schmorl’s nodes can develop for several reasons. Some are thought to occur during growth in adolescence, when the endplates are not yet fully mature, and may relate to genetic factors or developmental variations in bone strength. Others form gradually in adulthood from chronic mechanical loading, degenerative disc disease, or repetitive stress on the spine. Less commonly, a Schmorl’s node can develop acutely after an injury, heavy lifting, or significant trauma, and these acute lesions are more likely to be associated with symptoms. Conditions that weaken the bone—such as osteoporosis, certain inflammatory disorders, infection, or rarely tumors—can also predispose to Schmorl’s node–like changes, although typical Schmorl’s nodes themselves are not signs of these conditions.
Most Schmorl’s nodes cause no symptoms at all and are found incidentally on MRI, CT, or X-ray performed for unrelated reasons. When symptoms do occur, they are most often localized back pain near the affected vertebra, sometimes worsened by certain movements or activities. Acute (newly formed) Schmorl’s nodes are more likely to be painful and often show surrounding bone marrow edema on MRI, reflecting the body’s response to the recent change in the endplate. Over time, this edema typically resolves, and the Schmorl’s node becomes a stable, asymptomatic finding.
MRI of the spine is the preferred imaging test for evaluating a suspected Schmorl’s node because it shows the disc, endplates, and bone marrow signal in detail. MRI can distinguish between an old, stable Schmorl’s node and an acute or symptomatic one based on the presence or absence of surrounding bone marrow edema. CT and X-ray are useful for confirming the bony defect in the endplate but provide less information about activity or inflammation. In the rare cases where imaging features are atypical—such as unusually large lesions, aggressive-appearing changes, or findings suspicious for infection or tumor—additional evaluation may be needed.
Important to Know
For the great majority of people, a Schmorl’s node is a harmless incidental finding that does not require treatment, activity restriction, or follow-up imaging. When back pain is present, it is usually due to another cause such as muscle strain, degenerative disc disease, or facet arthropathy, even when a Schmorl’s node is present on imaging. In patients with an acute, painful Schmorl’s node, conservative care—including activity modification, physical therapy, posture and ergonomic adjustments, and anti-inflammatory medications—is typically effective, and follow-up imaging usually shows resolution of the surrounding edema over time.
Because Schmorl’s nodes are so common, accurate identification on imaging helps avoid unnecessary testing or concern. Imaging findings are always interpreted together with the patient’s symptoms and overall clinical picture.
Red flag symptoms include sudden severe back pain (especially after even minor trauma in older adults), progressive weakness or numbness, gait or balance difficulty, loss of bowel or bladder control, fever or chills with back pain, unexplained weight loss, or night pain that wakes the patient from sleep. These warrant prompt medical evaluation, as they may indicate fracture, infection, or another serious underlying condition rather than a simple Schmorl’s node.