Hafe of my thumb is numb.?

Trauma?: If there was no trauma to the thumb or any other joint on that extremity, the next condition to think about is ulnar nerve entrapment at the elbow. Would suggest a neurologist for possible nerve testing or an orthopedic for evaluation.

Not the ulnar nerve: The ulnar nerve does not go to the thumb. It gives sensation to the ring and little fingers and the ulnar border of the hand. The median nerve gives feeling to the thumb.