My Grandfather in the Hospital

My grandfather is sick and was recently admitted to the hospital sometime last week. There is a lack of communication and I didn’t find out until a few days after it happened. When I spoke to either of my parent’s they both said “You didn’t know?”, but how would I know if they didn’t tell me? The next big questions are: What happened? And why is he there? Nobody seems to have a definite answer.
My grandmother unfortunately is very overwhelmed with taking care of my sick grandfather and with him now in the hospital. I live over an hour away and unfortunately I can’t visit as much as I would like. To find out what is going on I have to depend on asking my parents whom I can’t seem to get a definite answer from. Instead of speaking to the doctor themselves they listen to my grandmother so not to offend her and her ability to find out what is going on. My grandmother listens to what the doctor says and believes that he/she knows best. Once the information is relayed from her, who doesn’t fully understand what is happening medically, to my parents, who also don't fully understand, and then to me the story becomes unclear. So the story I am getting about what is wrong with my grandfather and what is going on is not a clear one and doesn’t seem to make much sense at all. It is hard to see my grandfather sick and to not understand even what is actually wrong.