Massage lead to hand swelling?

I've recently taken to getting a relaxation massage on Thursday afternoons. VERY light pressure. It really has helped me relax and made my body much better after a week of Pilates and running on the treadmill, etc. However, at the end of the massage my hands are swollen and stiff and painful. Only for a few minutes, but it's just something that interests me. What would cause that, I wonder? (Going to bed at night does the same thing, cuz they're like that every morning too.)

Swollen hands was my first real tangible symptom, for me. At first my left middle finger "triggered," or locked, staying stiff, then another couple fingers, and then my left hand swelled up so none of the fingers could bend. Sometimes it goes away during the workday, sometimes not. That started before I got on meds. Now that I take meds (gabapentin and cyclobenzaprine) the stiffness has eased somewhat, but I still did away with childproof caps, and sometimes suddenly drop things because of the swelling on the nerves. I had to stop wearing my beautiful rings, or my fingers fall asleep frequently.