Your healthcare provider might not be able to narrow down the exact cause of your cubital tunnel syndrome. Possible causes include:
- Anatomy: Over time, the soft tissues over your ulnar nerve might get thicker, or there might be extra muscle. Both of those issues can stop your nerve from working right and cause cubital tunnel syndrome.
- Pressure: A seemingly simple use of your elbow, like leaning it on an armrest, can press on the ulnar nerve. When the nerve gets compressed, you might feel your arm, hand, ring finger and pinky finger fall asleep.
- Snapping: Your ulnar nerve might not stay where it’s supposed to. It might snap over the medial epicondyle when you move it. Snapping it repeatedly irritates the nerve.
- Stretching: If you bend your elbow for a long time, like when you sleep, you might overstretch the nerve. Too much stretching could result in cubital tunnel syndrome.