Late last night my right thumb started hurting when used. Even after I went to bed, some movement in arranging my bed clothes caused sharp pain, so I got up and stumbled to the home office there to find and put on an old wrist brace. It only restricts the biggest movements, but it maintains a low level of awareness that something is not right. Unfortunately, maintaining a low level of awareness while sleeping means reduced sleep quality, so I am rather tired today. And I'm still wearing the brace. So far I seem able to work though, I just write more slowly.