This is arthritis that affects the joint at the base of the thumb. We call this the "basal," (or "carpometacarpal") joint. Arthritis here makes it hard for you to do tasks that require pinching or gripping.
What causes arthritis at this joint? For many, it's from the normal wear and tear of aging. It can develop if you injure your thumb. It can happen if you do repetitive tasks that stress this joint. Certain hereditary conditions also make you more likely to have this arthritis.
What are the symptoms? You feel pain and tenderness at the base of your thumb, especially when you pinch or grip. You can have swelling. Your thumb may feel stiff, and you may not be able to move it through its full range of motion. It may feel weak. And you may see a bony enlargement at the base of your thumb.
How do we treat it? You may benefit from things like heat, ice, and the use of adaptive tools to help with some tasks. For example, changing door knobs to lever-style handles will make doors easier to open. You may also benefit from medications and injections. We may recommend a splint to support your thumb. If these don't help, you may need surgery. Your doctor will create a plan that's right for you.