Cubital tunnel syndrome is a condition brought on by increased pressure on the ulnar nerve at the elbow.

There is a bump of bone on the inner portion of the elbow under which the ulnar nerve passes. This site is commonly called the “funny bone”. At this site, the ulnar nerve lies directly next to the bone and is susceptible to pressure. When the pressure on the nerve becomes great enough to disturb the way the nerve works, numbness, tingling, and pain are felt in the elbow, forearm, hand, or fingers.

What Causes Cubital Tunnel Syndrome?

Cubital tunnel syndrome occurs when the pressure on the nerve is significant and sustained enough to disturb the way the ulnar nerve works.

Pressure on the ulnar nerve at the elbow can develop in several ways. The nerve is positioned right next to the bone and has very little padding over it, so pressure on this can put pressure on the nerve. For example, if you lean your arm against a table on the inner part of the elbow, your arm may fall asleep and be in pain from sustained pressure on the ulnar nerve. If this occurs repetitively, the numbness and pain may be more persistent and frequent. In some patients, the ulnar nerve at the elbow begins to click back and forth over the bony bump as the elbow is bent and straightened. If this occurs repetitively, the nerve may be significantly irritated.

Additionally, pressure on the ulnar nerve can occur from holding the elbow in a bent position for a long time, which stretches the nerve across the medial epicondyle. Such sustained bending of the elbow tends to occur during sleep. Sometimes the connective tissue over the nerve becomes thicker, or there may be variations in the muscle structure over the nerve at the elbow that put pressure on the nerve.

How do I know if I have Cubital Tunnel Syndrome?

Cubital tunnel syndrome symptoms include pain, numbness, and tingling. The numbness or tingling most often occurs in the ring and little fingers. The symptoms are usually felt when there is pressure on the nerve, such as sitting with the elbow on an arm rest, or with repetitive elbow bending and straightening. Often symptoms will be felt when the elbow is held in a bent position for a period of time, such as when holding a phone or sleeping. Some patients may notice weakness while making a pinching motion and occasional clumsiness.