Large Liver Cyst

I was feeling abdominal pain in the solar plexus region when I did floor exercises on my stomach. My doctor recommended an ultrasound which showed that I had a large cyst on my liver. I was scheduled to get it drained at the hospital and they removed 350 ml of fluid! I'm not sure what causes this but have found a diet with lots of fiber and drinking lots of water seems to alleviate the nausea I can develop. Wish I knew what causes the cysts.