What causes cubital tunnel syndrome?

Cubital tunnel syndrome is what we call an entrapment neuropathy. Which just means that a specific nerve is getting pinched, because it has less room in the body. In cubital tunnel, it's the ulnar nerve that's getting pinched at the elbow. This can occur of because the elbows are bent, or traumatized right over ulnar nerve.

So, when people get numbness and tingling in their hands, when they've been on the phone for a long period of time, either for work, or just talking on their cell phones; that's often the ulnar nerve getting pinched. Similarly, when people sleep with their elbows bent, which is a common way to sleep, the ulnar nerve can be compressed even more so. And can wake you up at night, causing that numbness and tingling feeling.