My mother who is 48 yrs old is experiencing a swelling on her left knee. Her weight is 79kg. She has been experiencing some leg pains and foot pain as well. So she went to an orthopedist and he told her that there is some liquid accumulated on the knee so it needs to be taken out , also he says that it would be a problem if the liquid comes back again. So have some tests to do tomorrow. But I am worried as I don't know whether the condition is bad for her or not. Please help. I am also visiting another doctor tomorrow but meanwhile I would like to know a little from you as well. Thanks.