Worried

My mom was admitted to the hospital for a few days last week due to a bladder infection which led to dehydration and a low blood sodium level. They released her Tuesday and she seemed to be doing well. She went back in the hospital this morning again. Her blood sodium level is very low again and she is extremely confused. The doctors say that low sodium does often cause confusion, but it is very scary. Phil and I will be going out to see her later today. I hope that the doctors can provide some answers as to why her sodium is so low. I talked to my sister a while ago. She was at the hospital earlier. She said that the doctors said my mom's sodium level was in the 120 range. I googled "normal blood sodium level" and it said normal levels should be 136 to 145. Not good! I'll let everyone know when I have found out more as to what is causing this.