Annular fissure

What it means

Each spinal disc has a soft, gel-like center held inside a tough outer ring of fibers called the annulus. An annular fissure — also called an annular tear — is a crack that develops within that outer ring. It reflects the ordinary wear the ring takes over the years and does not, by itself, mean the disc has slipped or herniated.

Why it appears on a CT or MRI report

MRI shows these fissures, sometimes as a small bright spot in the back of the disc (a "high-intensity zone"). Reports name the disc level and may note whether the fissure is associated with a bulge or with any pressure on nearby nerves. The wording is often neutral — "annular fissure" or "annular tear at L4-L5" — because the finding is frequently just one part of the disc's normal aging, described for completeness.

What it usually means

Annular fissures are common and are found in many people with no back pain at all, which makes them tricky to interpret. In some cases the outer ring is richly supplied with nerve endings, so a fissure there can be a genuine pain source; in many others it is silent. Because the finding overlaps so heavily between people with and without symptoms, treatment follows how you actually feel rather than the tear itself. Most disc-related back pain, including pain linked to a fissure, improves with time, staying active, and physical therapy, without any procedure aimed at the crack.

When to follow up

Discuss the report with your doctor if you have back pain that limits daily life. Seek prompt care for warning signs that point beyond a simple fissure: leg weakness, numbness in the saddle area, loss of bladder or bowel control, or severe pain radiating down a leg. These suggest a nerve is involved and change the plan, whereas an isolated annular fissure usually does not.

A plain-language way to picture it

Imagine a jelly-filled donut whose outer dough develops a fine crack with age. The jelly is still inside, and the donut still holds its shape — nothing has burst out. The crack is a sign of wear in the wrapping, and most of the time it simply sits there. Only if the wrapping gives way and the jelly pushes out does it become the different problem of a herniation.