“Compression at the elbow, known as cubital tunnel syndrome, causes numbness in the small finger
, half of the ring finger
, and the back half of the hand over the small finger
. Initially, the numbness is transient and usually occurs in the middle of the night or in the morning. Most cases will be minor and tend to come and go with time. Common causes are sleeping with the arm folded up, so the hand is at the person's neck and the elbow is sharply bent.