Cubital Tunnel Syndrome: Symptoms, Causes, Diagnosis, and Treatment
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 17, 2026
Quick Answer
Cubital tunnel syndrome is irritation or compression of the ulnar nerve at the inside of the elbow. Hallmark signs are inner elbow pain and numbness or tingling in the pinky and ring finger, especially with the elbow bent. See a doctor if symptoms last more than six weeks. Treatment starts with bracing, exercises and NSAIDs, with surgery for unresolved cases. [1]
What the research says
It is a common nerve compression, and most mild cases improve without surgery. A review describes cubital tunnel syndrome as the second most common compressive neuropathy of the upper extremity; nonsurgical treatment, aimed at reducing compression and traction on the nerve, is successful in most patients with mild nerve dysfunction, and randomized trials have not identified a preferred surgical procedure (Staples & Calfee, Journal of the American Academy of Orthopaedic Surgeons, 2017) [2].
Simple decompression is the most common operation. An EFORT Open Reviews article notes that no single surgical technique has been shown to be superior, and that simple decompression is the most commonly used because of its efficacy and low complication rate (Burahee et al., EFORT Open Reviews, 2021) [3].
Surgery helps most people, but not everyone. In a study of 21 patients who had cubital tunnel decompression surgery, 16 improved and 5 did not, and persistent symptoms can remain depending on how severe the nerve injury was (Kim et al., European Radiology, 2023) [4].
What Is Cubital Tunnel Syndrome?
Cubital tunnel syndrome, also called ulnar nerve entrapment, happens when your ulnar nerve gets irritated or compressed (squeezed) at the inside of your elbow. [1]
Nerves are bundles of string-like fibers that send and receive messages between your brain and your body through electrical and chemical changes in their cells. Your arm contains three main nerves: the median, the ulnar, and the radial. The ulnar nerve runs from your neck down your arm to your hand. [1]
The ulnar nerve travels through a tunnel of tissue called the cubital tunnel, which passes under a bony bump on the inside of your elbow called the medial epicondyle. The space is narrow, and only a little tissue protects the nerve there. That spot is where the ulnar nerve is most vulnerable. [1]
After passing the medial epicondyle, the ulnar nerve continues under the muscles on the inside of your forearm and into your hand, on the side that contains your little finger (pinky). When it enters the hand, it passes through a second tunnel called Guyon's canal. [1]
Because of your ulnar nerve, you can control some of the larger muscles in your forearm that help you grip objects, feel your little finger, feel half of your ring finger, and control many of the small muscles in your hand. Those hand muscles let you perform fine movements such as typing on a keyboard or playing a musical instrument. [1]
Where the ulnar nerve is compressed at the inside of the elbow, what it controls, and the key risk factors.
Cubital Tunnel Syndrome at a Glance
Key Fact | Detail |
Other name | Ulnar nerve entrapment (at the elbow) |
What happens | The ulnar nerve is irritated or compressed at the inside of the elbow |
Affected fingers | The pinky and half of the ring finger |
Where it happens | The cubital tunnel, under the medial epicondyle (inside of the elbow) |
Most common symptoms | Inner elbow pain plus numbness and tingling in the hand, usually when the elbow is bent |
What untreated compression can cause | Muscle weakness and muscle wasting (atrophy) in the hand |
First-line treatment | Nonsurgical: bracing, exercises, hand therapy, NSAIDs |
When surgery is considered | When nonsurgical treatment fails, compression is severe, or muscle weakness develops |
The "Funny Bone" Is Actually a Nerve
Did you know that your funny bone isn't a bone? It's a nerve. That unique, almost electric sensation you feel when you hit your funny bone is actually compression of your ulnar nerve. [1]
That everyday experience is a small version of what happens in cubital tunnel syndrome, except with this condition the compression is repeated or prolonged rather than momentary.
Who Is at Risk for Cubital Tunnel Syndrome?
Several factors raise your risk of developing cubital tunnel syndrome. Having these factors does not mean you will automatically get the condition; it means your risk is higher than the average person's. [1]
Risk Factor | How It Raises Your Risk |
Arthritis of the elbow | Joint changes can irritate or crowd the nerve |
Bending your elbow for a long time | Prolonged bending overstretches the nerve |
Bone spurs | Bony growths can press on the nerve |
Cysts near the elbow joint | Lumps of fluid can crowd the narrow tunnel |
Past elbow dislocation | Old injury changes the anatomy around the nerve |
Past elbow fracture | Healed fractures can alter the nerve's pathway |
Swelling of the elbow joint | Extra fluid narrows the already-tight tunnel |
Cubital Tunnel Syndrome vs. Carpal Tunnel Syndrome
People often confuse the two conditions because both involve compressed nerves in the arm. The key difference is which nerve is affected and which fingers feel it.
Feature | Cubital Tunnel Syndrome | Carpal Tunnel Syndrome |
Nerve involved | Ulnar nerve | Median nerve |
Fingers affected | Pinky and ring finger | Thumb, index finger, and middle finger |
Compression site | Inside of the elbow | Wrist |
What Causes Cubital Tunnel Syndrome?
Your healthcare provider might not be able to pinpoint the exact cause of your cubital tunnel syndrome. Possible causes fall into four groups. [1]
Cause | What Happens |
Anatomy | Over time, the soft tissues over your ulnar nerve might get thicker, or there might be extra muscle; both can stop the nerve from working right |
Pressure | A simple habit like leaning your elbow on an armrest can press on the ulnar nerve; when compressed, the arm, hand, ring finger, and pinky can "fall asleep" |
Snapping | The ulnar nerve might not stay in place and can snap over the medial epicondyle with movement; snapping it repeatedly irritates the nerve |
Stretching | Bending your elbow for a long time, such as when you sleep, can overstretch the nerve |
What Are the Symptoms of Cubital Tunnel Syndrome?
Inner elbow pain and numbness and tingling in your hand are the most common symptoms. This happens most often when your elbow is bent, for example when you drive, hold a phone, or sleep. [1]
Symptom | What It Feels Like |
Numbness in hand and fingers | Comes and goes; most often affects the pinky and ring finger |
Tingling in hand and fingers | A "pins and needles" sensation that comes and goes |
Pain on the inside of your elbow | Aching near the medial epicondyle |
Difficulty moving fingers | Harder to move fingers when they are numb or tingling ("falling asleep") |
Symptoms are most common when the elbow is bent: driving, holding a phone, or sleeping.
When to see a doctor. See your healthcare provider if you have had these symptoms for more than six weeks or if they are severe. You could develop muscle wasting in your hand if you wait too long to treat the compressed nerve. The good news is that with treatment, your symptoms should improve or go away. [1]
How Is Cubital Tunnel Syndrome Diagnosed?
Your healthcare provider will likely begin by asking questions about your symptoms, then order several tests to confirm the picture. [1]
Diagnostic Tool | What It Shows |
Symptom history | Questions about your symptoms, how long they have lasted, your medications, and past injuries |
Blood tests | Checks for diabetes or thyroid disease, which can affect nerves |
Electromyogram (EMG) | Shows how your nerves and nearby muscles are acting |
X-rays | Checks for bone spurs, arthritis, and places where bone might compress the ulnar nerve |
During the appointment, expect questions like these: What are your symptoms, and how long have you had them? What medications do you take? Do you feel numbness, a falling-asleep sensation in your hand or fingers, or pins and needles? How bad is the pain? Are you still able to perform fine movements like typing? Have you ever had a fractured or dislocated elbow?
How Is Cubital Tunnel Syndrome Treated?
Both surgical and nonsurgical treatments exist for cubital tunnel syndrome. Healthcare providers prefer non-invasive treatments first and usually start with the nonsurgical options. [1]
Nonsurgical Treatment (First Line)
Treatment | How It Helps |
Bracing or splinting | A padded brace or splint worn at night helps keep your elbow straight |
Nerve gliding exercises | Help the ulnar nerve slide more easily through the cubital tunnel and may prevent stiffness in your arm and wrist |
Hand therapy | A hand therapist teaches ways to avoid putting pressure on your ulnar nerve |
NSAIDs | Ibuprofen (Advil, Motrin) can reduce swelling around the nerve and lessen pain |
One nerve gliding exercise you could try: hold your arm in front of you with your elbow straight, then curl your wrist and fingers toward your body. Next, push them away from you and bend your elbow. Check with your healthcare provider first to see if nerve gliding exercises are right for you.
Surgical Treatment
If nonsurgical treatments do not improve your symptoms, your nerve is very compressed, or the compression has caused muscle weakness, your provider might recommend surgery. You will be referred to an orthopaedic surgeon. [1]
Surgery | What It Does |
Cubital tunnel release | The ligament that forms the roof of the tunnel is cut and divided, making the tunnel bigger and decreasing pressure on the ulnar nerve; new tissue grows where the ligament was cut |
Ulnar nerve anterior transposition | The ulnar nerve is moved from behind the medial epicondyle to the front (closest to your skin), so it cannot catch on the bone |
Medial epicondylectomy | Part of the medial epicondyle is removed to release the nerve |
These procedures are usually outpatient, but you might stay one night at the hospital. You will likely wear a splint on your arm for about two to three weeks, and physical therapy is sometimes necessary to regain motion and strength. Surgery does not guarantee the syndrome will go away permanently, but the outcome is generally positive. [1]
Nonsurgical treatment comes first; surgery is for cases that do not improve or involve muscle weakness.
How Long Does Recovery Take?
Recovery can take many months. Nerves do not heal as quickly as other parts of your body. [1]
What Happens if Cubital Tunnel Syndrome Goes Untreated?
If you do not get treatment, you might develop atrophy, which is muscle wasting in your hand. Your muscles could weaken, and your hand might look bony and not function as well. [1]
How Can I Reduce My Risk?
Although it might not be possible to prevent cubital tunnel syndrome entirely, a few habits can help reduce your risk. [1]
Prevention Habit | Why It Helps |
Avoid leaning on your elbow | Removes direct pressure on the nerve |
Avoid pressure on the inside of your arm | Keeps the narrow tunnel free from compression |
Skip the chair armrest | Don't rest your elbow on a computer chair armrest you use frequently; keep your chair high |
Sleep with your elbow straight | Prevents prolonged stretching of the nerve overnight |
Avoid long periods of bent-arm posture | Staying away from anything that makes you bend your arm for a long time protects the nerve |
When Should I Contact My Healthcare Provider?
Contact your healthcare provider if your symptoms are severe or have lasted for more than six weeks. Getting treatment matters because cubital tunnel syndrome can weaken and shrink the muscles in your hand (muscle wasting), causing clumsiness and additional pain. No one wants to be in pain all day. You do not have to live with the symptoms; treatment can improve your quality of life, and the sooner you get treatment, the sooner you will feel less pain. [1]
Questions to Ask Your Doctor
Question | Why It Matters |
What caused my cubital tunnel syndrome? | Identifies the mechanism (pressure, snapping, stretching, anatomy) |
What nonsurgical methods of treatment should I try? | Covers bracing, exercises, therapy, and medications |
Do I need surgery? | Determines whether compression or muscle weakness warrants an operation |
Will I have to stay overnight after surgery? | Most procedures are outpatient, but an overnight stay is possible |
Do I need physical therapy? | Helps regain motion and strength after treatment |
How long will it take my nerve to heal? | Nerves heal slowly; recovery can take many months |
Conclusion
Cubital tunnel syndrome is irritation or compression of the ulnar nerve at the inside of your elbow, where the nerve passes through a narrow, poorly protected tunnel under the medial epicondyle. It produces inner elbow pain and numbness or tingling in the pinky and half of the ring finger, especially when the elbow is bent during driving, phone use, or sleep. Unlike carpal tunnel syndrome, which affects the thumb side of the hand, cubital tunnel syndrome affects the pinky side. Most cases improve with nonsurgical care: night bracing, nerve gliding exercises, hand therapy, and NSAIDs. Surgery is reserved for stubborn or severe cases and usually has a positive outcome. Because untreated compression can waste the hand muscles, do not wait it out: symptoms lasting more than six weeks are a clear signal to see a healthcare provider.
If your pinky and ring finger keep falling asleep, your elbow aches on the inside, or symptoms have lingered for more than six weeks, talk to a healthcare provider about cubital tunnel syndrome. Early treatment protects the small muscles of your hand and the fine movements they make possible.
Frequently Asked Questions
What is cubital tunnel syndrome?
Cubital tunnel syndrome, also called ulnar nerve entrapment, happens when the ulnar nerve is irritated or compressed at the inside of the elbow, where it passes through a narrow tissue tunnel under a bony bump called the medial epicondyle.
How common is cubital tunnel syndrome?
Cubital tunnel syndrome is a common cause of arm and hand numbness, and research describes it as the second most common compression neuropathy of the upper limb. The ulnar nerve is most vulnerable at the elbow because the cubital tunnel is narrow and has little protective tissue.
What causes cubital tunnel syndrome?
Possible causes include thickened soft tissue or extra muscle around the nerve (anatomy), direct pressure such as leaning on an armrest, the nerve snapping repeatedly over the medial epicondyle with movement, and prolonged stretching from keeping the elbow bent for long periods, such as during sleep.
How do you get cubital tunnel syndrome?
You can develop it through repeated pressure on the inside of the elbow, prolonged elbow bending, prior elbow fractures or dislocations, bone spurs, elbow arthritis, joint cysts, or joint swelling. Sometimes the exact cause cannot be determined.
What are the symptoms of cubital tunnel syndrome?
The most common symptoms are pain on the inside of the elbow and numbness and tingling in the hand, most often when the elbow is bent, such as while driving, holding a phone, or sleeping. Difficulty moving fingers when they are numb or tingling can also occur.
Is cubital tunnel syndrome the same as carpal tunnel syndrome?
No. Cubital tunnel syndrome affects the ulnar nerve at the elbow and involves the pinky and ring finger. Carpal tunnel syndrome affects the median nerve at the wrist and involves the thumb, index finger, and middle finger.
How is cubital tunnel syndrome treated?
Treatment starts with nonsurgical options: a padded night brace to keep the elbow straight, nerve gliding exercises, hand therapy, and NSAIDs such as ibuprofen. If these fail, or compression is severe or causing muscle weakness, surgery (cubital tunnel release, anterior transposition, or medial epicondylectomy) may be recommended.
How long does cubital tunnel syndrome last?
Recovery can take many months because nerves heal more slowly than other body tissues. Symptoms lasting more than six weeks should be evaluated by a healthcare provider.
What happens if cubital tunnel syndrome is not treated?
Untreated compression can lead to atrophy, or muscle wasting, in the hand. Muscles can weaken and the hand may look bony and not function as well. With treatment, symptoms should improve or go away.
Can cubital tunnel syndrome be prevented?
It may not be possible to prevent it entirely, but you can reduce risk by avoiding leaning on your elbow, avoiding pressure on the inside of your arm, not resting your elbow on a frequently used chair armrest, sleeping with your elbow straight, and avoiding long periods of a bent-arm posture.
External Resources
Related Reading
Learn more in our guide to Elbow Surgery: Types, Procedure, Risks and Recovery.
Tinel's Sign: What It Is, How the Test Works and What a Positive Result Means explains the quick tapping test providers use to check for nerve compression.
References
Cleveland Clinic. Cubital Tunnel Syndrome. Cleveland Clinic. Medically reviewed; last updated October 25, 2021. https://my.clevelandclinic.org/health/diseases/21997-cubital-tunnel-syndrome
Staples JR, Calfee R. Cubital tunnel syndrome: current concepts. Journal of the American Academy of Orthopaedic Surgeons. 2017;25(10):e215-e224. PMID 28953087. https://doi.org/10.5435/JAAOS-D-15-00261
Burahee AS, Sanders AD, Shirley C, Power DM. Cubital tunnel syndrome. EFORT Open Reviews. 2021;6(9):743-750. PMID 34667645. https://doi.org/10.1302/2058-5241.6.200129
Kim KH, Lee MH, Park SY, et al. Ulnar neuropathy at the elbow: associations of pre-operative DTI parameters with clinical outcomes after cubital tunnel decompression. European Radiology. 2023;33(9):6351-6358. PMID 37014404. https://doi.org/10.1007/s00330-023-09562-8
Medical disclaimer
This article is for general educational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. See a healthcare provider if you notice weakness, muscle wasting in the hand, or symptoms that last more than six weeks.
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