A 60-year-old female patient complains of pain in both hands that is worse in the morning

Psychology Oct 16, 2020

A 60-year-old female patient complains of pain in both hands that is worse in the morning. On physical examination, the thumb metacarpophalangeal joint is swollen on both hands. There is swelling of the proximal and distal interphalangeal joints bilaterally. What is the diagnosis and why?