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Hand & Wrist

Guyon's Canal Syndrome: ulnar nerve compression at the wrist.

Numbness and tingling in the ring and small fingers, sometimes with grip or pinch weakness, from pressure on the ulnar nerve as it passes through Guyon's canal at the wrist. It is distinct from cubital tunnel syndrome, where the same nerve is pinched at the elbow.

Written bySteven J. Lee, MD · Double Fellowship-Trained · Hand & Sports Medicine
Last reviewed · June 2026

Guyon's canal syndrome is compression of the ulnar nerve as it travels through Guyon's canal, a narrow passage on the small-finger side of the palm side of the wrist. When the nerve is squeezed in this canal, it produces numbness and tingling in the ring and small fingers, and in some patients weakness of grip and pinch.

Because the ulnar nerve can also be compressed at the elbow, where the problem is called cubital tunnel syndrome, telling the two apart is an important part of the evaluation. The pattern of numbness, the presence or absence of certain hand weakness, and nerve testing all help locate exactly where the nerve is being pinched.

Anatomy and causes

Guyon's canal is bordered by two small wrist bones and a roof of ligament. Within or near the canal the ulnar nerve divides into branches that supply sensation to the ring and small fingers and power to many of the small muscles of the hand. Pressure anywhere along this path produces symptoms.

Common causes include a ganglion cyst pressing on the nerve, repetitive or sustained pressure on the base of the palm, trauma such as a wrist fracture, and prolonged gripping. A classic example is the cyclist who develops numbness and weakness after long rides leaning on the handlebars, sometimes called handlebar palsy.

Symptoms

Typical complaints include:

  • Numbness and tingling in the ring and small fingers
  • Weakness of grip or pinch, or clumsiness with fine tasks
  • Symptoms brought on by sustained pressure on the palm, such as cycling
  • In longer-standing cases, visible wasting of the small muscles of the hand

Guyon's canal versus cubital tunnel

Both conditions involve the ulnar nerve and both can cause ring and small finger numbness, which is why they are often confused. The key difference is the location of the compression: Guyon's canal is at the wrist, cubital tunnel is at the elbow. The back of the small-finger side of the hand and certain hand muscles are affected differently depending on the site, and a nerve conduction study can confirm where the nerve is being pinched. Identifying the correct level is what makes treatment effective.

How it is diagnosed

Diagnosis combines the clinical exam with nerve testing. The exam maps where numbness and weakness are present and checks for a cyst or a point of tenderness at the wrist. An electrodiagnostic study (EMG/NCV) measures how well the ulnar nerve is conducting and helps localize the compression to the wrist rather than the elbow. Imaging such as ultrasound or MRI is used when a ganglion cyst or other mass is suspected as the cause.

Dr. Lee's approach

Many cases of Guyon's canal syndrome improve once the source of pressure is identified and removed. Dr. Lee starts with activity and ergonomic modification, padded gloves and handlebar changes for cyclists, a supportive splint, and treatment of any underlying ganglion cyst that is compressing the nerve.

When compression persists despite these measures, or when there is weakness or muscle wasting, Dr. Lee performs a surgical decompression of Guyon's canal that releases the roof of the canal and frees the ulnar nerve. If a cyst is the cause, it is removed at the same time. The priority is to relieve pressure before the nerve sustains lasting damage.

Non-surgical treatment

Most early cases begin here:

  • Activity and ergonomic modification, including padded gloves and handlebar adjustments for cyclists
  • A wrist splint to rest the nerve and limit provoking positions
  • Treating an underlying ganglion cyst that is pressing on the nerve
  • Anti-inflammatory measures for symptom control

Surgical decompression

When symptoms persist or there is weakness, the roof of Guyon's canal is released through a small incision so the ulnar nerve is no longer compressed. If a ganglion cyst is responsible, it is excised at the same time. The procedure is outpatient, and the technical priority is protecting the branches of the ulnar nerve as the canal is opened.

Recovery timeline

Recovery after a decompression is usually steady:

  1. Day 0 to 7
    Soft dressing and a light splint. Use the hand for daily activities. Keep the wound dry until the first visit.
  2. Weeks 1 to 2
    Sutures removed. Begin gentle motion. Tingling often begins to settle as the nerve recovers.
  3. Weeks 2 to 6
    Progressive strengthening and return to gripping. Numbness improves over weeks; long-standing weakness recovers more slowly.

What patients commonly misunderstand

A few points worth clearing up:

  • It is not the same as carpal tunnel. Carpal tunnel affects the median nerve and the thumb side of the hand. Guyon's canal affects the ulnar nerve and the ring and small fingers. The treatments differ, so an accurate exam matters.
  • The same numbness can come from the elbow. Cubital tunnel syndrome at the elbow can cause the same ring and small finger numbness. Locating where the nerve is pinched, at the wrist or the elbow, changes the treatment.
  • A cyst is a common and treatable cause. When a ganglion cyst is pressing on the nerve in the canal, removing the cyst often relieves the compression directly.

This page is general educational content authored by Dr. Lee. It is not a substitute for individual medical advice. Every patient's case is different, book a consultation to discuss yours.

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Patient questions

Guyon's canal syndrome, answered.

  • What is Guyon's canal syndrome?

    Guyon's canal syndrome is compression of the ulnar nerve as it passes through Guyon's canal, a narrow passage on the small-finger side of the wrist. It causes numbness and tingling in the ring and small fingers, and sometimes weakness of grip and pinch. Common causes include a ganglion cyst pressing on the nerve, sustained pressure on the palm (as in cycling), and wrist trauma.

  • How is it different from cubital tunnel syndrome?

    Both conditions involve the ulnar nerve and can cause numbness in the ring and small fingers. The difference is where the nerve is compressed: Guyon's canal syndrome is at the wrist, while cubital tunnel syndrome is at the elbow. A clinical exam and a nerve conduction study help localize the compression, which determines the correct treatment.

  • Why do cyclists get this?

    Leaning body weight on the handlebars for long rides puts sustained pressure on the base of the palm, where the ulnar nerve runs through Guyon's canal. This can produce numbness and weakness sometimes called handlebar palsy. Padded gloves, handlebar adjustments, and changing hand position often relieve the pressure and the symptoms.

  • Does it always need surgery?

    No. Many cases improve once the source of pressure is identified and removed, using activity and ergonomic modification, splinting, and treatment of any underlying cyst. Surgery to decompress Guyon's canal is considered when symptoms persist despite these measures, or when there is weakness or muscle wasting that indicates the nerve is under ongoing pressure.

Next step

Ring and small finger numbness that will not settle? Find out where the nerve is pinched.

Ulnar nerve symptoms can come from the wrist or the elbow, and the treatments differ. The first step is an accurate diagnosis that locates the compression, so the right treatment can relieve it before the nerve is damaged.

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