<s>[INST] What is heart failure? [/INST] Heart failure means that the heart is not functioning properly and is unable to pump enough blood to meet all of the body’s needs. Heart failure causes muscles to weaken which hinders proper blood circulation through the body. This can cause weakness and fatigue, and blood to back up which can cause fluid to leak from the blood vessels into tissues, causing congestion. Source: BCM EDU. Link: https://www.bcm.edu/healthcare/specialties/cardiovascular-medicine/specialty-centers-and-programs/advanced-heart-failure-clinic/heart-failure-faqs. Field: Cardiovascular. Disease: Heart Failure </s>