Dr. Tamara Clancy answers your questions about thumb arthritis, also known as arthritis base of the thumb.
What is the painful bump at the base of my thumb?
This is more than likely wear-and-tear arthritis, and the bump is one of the bones (metacarpal) that becomes prominent as the joint wears out (cartilage thins).
What is the cause?
The cause is the cartilage in the joint thinning out. Some of this is genetic (inherited). Injury and joint laxity (being “double-jointed”) may contribute to developing this as well. It is also more common in women.
Is there any way to know if my pain will get worse?
No — this is a problem that usually gets worse as we get older, but there is no way to predict how rapidly the pain will progress in a particular person.