Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF typically presents with shortness of breath, excessive fatigue, and bilateral leg swelling.[3] The severity of the heart failure is mainly decided based on ejection fraction and also measured by the severity of symptoms.[7] Other conditions that have symptoms similar to heart failure include obesity, kidney failure, liver disease, anemia, and thyroid disease.[7]

Reference
Wiki: Heart dysfunction