My mom was admitted to the hospital with pneumonia. ..fluid around lungs...and conjestive heart failur...how dangerous is that..

Extremely: That is a description of a patient with critical illness.

Depends on specifics: Congestive heart failure occurs when the heart does not pump blood efficiently. This causes fluid to build up in the tissues especially the lungs. It is a serious condition, but it has many treatments. The prognosis depends on the cause, age of the patient and those kind of details. Pneumonia is a lung infection, seriousness varies depending on clinical details. It is also very treatable.