Understanding Heart Failure and How It Affects the Heart

Heart failure is a condition in which the heart’s pumping or filling ability is weakened, making it harder to deliver oxygen-rich blood to the body. It is not the same as a heart attack or cardiac arrest, though these can contribute to it. As the heart struggles, the body compensates by retaining salt and water and activating stress hormones, which can initially help but eventually worsen swelling, shortness of breath, and fatigue. Over time the heart muscle may become enlarged or stiff, electrical signaling can change, and pressure builds in the lungs and veins, leading to symptoms that affect daily life.

This article is for informational purposes only and should not be considered medical advice. Please consult a qualified healthcare professional for personalized guidance and treatment.

Heart failure causes and risk factors

Common causes include coronary artery disease and prior heart attacks that damage heart muscle, long-standing high blood pressure that forces the heart to work harder, and valve problems that create pressure or volume overload. Other contributors include diabetes, obesity, sleep apnea, viral infections that inflame the heart (myocarditis), genetic cardiomyopathies, excessive alcohol use, certain chemotherapy drugs, and long-term arrhythmias. Age increases risk as the heart and vessels stiffen, and risk patterns can differ across sexes and ethnic groups. Social factors such as access to preventive care, nutrition, and safe places to exercise also matter. Managing blood pressure, blood sugar, and cholesterol; avoiding tobacco; and addressing sleep apnea can reduce the likelihood of developing heart failure or slow its progression.

Early signs of heart failure

Early signs can be subtle. Many people notice shortness of breath during exertion or when lying flat, waking at night feeling breathless, or a persistent cough that worsens when reclined. Fluid buildup may cause swelling in the feet, ankles, legs, or abdomen, and a sudden increase in body weight over a day or two can be a tip-off that fluid is accumulating. Fatigue, reduced exercise tolerance, faster heartbeats or palpitations, and lightheadedness may occur. Some people experience loss of appetite, bloating, or confusion—especially older adults. Left-sided heart failure more often leads to breathing symptoms, while right-sided failure more often causes leg and abdominal swelling. Noticing patterns and tracking changes over time can help clinicians spot issues earlier.

Heart failure diagnosis process

Diagnosis begins with a careful history and physical exam, focusing on symptoms, medications, and conditions such as hypertension, diabetes, or thyroid disease. Blood tests often include markers of heart stress (BNP or NT-proBNP), kidney and liver function, electrolytes, and a complete blood count. An electrocardiogram (ECG) looks for rhythm problems or prior heart damage, and a chest X-ray can show heart enlargement or lung congestion. Echocardiography (ultrasound of the heart) is central to assessing structure, valve function, and ejection fraction (how much blood the left ventricle pumps with each beat). Some people need additional tests such as stress imaging, coronary CT angiography, cardiac MRI, or cardiac catheterization to clarify causes or guide treatment. Clinicians may describe heart failure with reduced ejection fraction or preserved ejection fraction, which helps tailor therapy. Accessing local services for imaging and follow-up in your area supports timely care.

Living with heart failure

Treatment typically combines guideline-directed medications and supportive care. Medications may include ACE inhibitors or ARBs, angiotensin receptor–neprilysin inhibitors, beta-blockers, mineralocorticoid receptor antagonists, and SGLT2 inhibitors, which together can reduce symptoms and hospitalizations. Diuretics help relieve fluid overload, and other drugs address rhythm issues or chest pain as needed. Some people benefit from devices such as implantable cardioverter-defibrillators (ICDs) or cardiac resynchronization therapy (CRT) when electrical conduction is impaired. Daily habits play a major role: monitoring weight, discussing sodium intake limits with a clinician, moderating fluid as advised, staying active with appropriate exercise or cardiac rehabilitation, updating vaccinations, treating sleep apnea, limiting alcohol, and avoiding smoking. Keeping a medication list, attending regular appointments, and seeking local services for education and support can improve stability.

Long-term heart failure outlook

The long-term outlook varies widely and depends on the cause, ejection fraction, age, kidney function, coexisting conditions, and how consistently therapies are used. Many people live for years with good symptom control when treatment plans are followed and risk factors are managed. Others experience frequent flare-ups, hospitalizations, arrhythmias, or worsening kidney function. Early engagement in heart failure clinics, nutrition support, and cardiac rehabilitation may improve quality of life. Remote monitoring tools, such as blood pressure cuffs and scales connected to care teams, can help spot problems before they escalate. Discussions about goals, advance care planning, and palliative care support can be appropriate at any stage, focusing on comfort, independence, and personal priorities. Understanding the condition and its triggers makes it easier to recognize changes and adjust care.

In sum, heart failure reflects a mismatch between what the body needs and what the heart can deliver. It alters the heart’s structure and signaling, and it affects lungs, kidneys, and circulation. Recognizing risk factors, noting early signs, following a clear diagnosis process, and adopting sustainable daily strategies can reduce symptoms and hospitalizations and support a more stable life over time.