Depends. Congestive heart failure or CHF can be from many things. Different types include systolic dysfxn wich means a weak heart. Usually from a virus, heart attack, or post partum.Diastolic dysfxn where the heart is stiff is usually due to hyer tension. High out put heart failure is when things such as hyperthyroidism or anemia . So your question is very broad and you need to narrow it down .
Multiple. Coronary artery disease (Angina) Diseases of the heart muscle (cardiomyopathy). High blood pressure (hypertension). Diseases of the heart valves. abnormal heart rhythms (arrhythmias). Medicines, alcohol excess, cocaine and some types of chemotherapy. Severe anaemia, thyroid disease (hypothyroidism or hyperthyroidism) and Paget's disease of bone.
Many. Weak heart muscles /hypertrophed heart / valve lek of moderate to severe degree valve narrowing -aoric stenosis /mitral stenosis hypertension to name a few.
Experts. Here's an expert monograph from the mayo clinic with a terrific explanation and list of causes: http://www.Mayoclinic.Com/health/heart-failure/ds00061/dsection=causes. Read more...