Heart Failure: Causes, Symptoms and Treatment

Heart Failure: Causes, Symptoms and Treatment

Heart failure does not mean the heart has stopped beating. It is a syndrome caused by problems with the heart’s structure or function. Blood flow may be inadequate, pressures inside the heart may be raised, or both; congestion can cause breathlessness and swelling.

What Is Heart Failure?

Heart failure occurs when the heart muscle contracts too weakly, relaxes too stiffly, or both. It affects millions of people worldwide and is one of the leading causes of hospitalisation in adults over 65.

Two commonly described patterns are:

• Systolic heart failure (HFrEF) — the heart muscle does not contract forcefully enough; the left ventricle ejects less blood than normal (reduced ejection fraction)
• Diastolic heart failure (HFpEF) — the heart muscle stiffens and cannot fill properly between beats; ejection fraction is preserved but filling is impaired

Symptoms can overlap, but the underlying physiology and treatment differ. Clinicians also recognise heart failure with mildly reduced ejection fraction (HFmrEF, 41–49%) and with improved ejection fraction. A preserved ejection fraction does not exclude heart failure; diagnosis also requires clinical assessment and evidence of abnormal filling pressures or other cardiac dysfunction.

Causes of Heart Failure

Cardiac Causes

Almost any heart condition can eventually cause heart failure. The most common include:

• Coronary artery disease — reduced blood flow to the heart muscle from blocked arteries; the leading cause worldwide
• Heart attack (myocardial infarction) — permanent damage to a region of the heart muscle after a blocked coronary artery
• High blood pressure (hypertension) — forces the heart to work harder over years, causing the walls to thicken and stiffen
• Heart valve disease — narrowed or leaking valves increase the heart's workload
• Cardiomyopathy — disease of the heart muscle itself, from genetic causes, viral infection, alcohol, or chemotherapy drugs
• Abnormal heart rhythms (arrhythmias) — rapid or irregular rhythms that prevent the heart from filling or emptying properly

Non-Cardiac Causes

• Uncontrolled diabetes and obesity (contribute to ventricular stiffness)
• Severe anaemia (forces the heart to work harder)
• Thyroid disorders — hyperthyroidism overstimulates the heart; hypothyroidism weakens it
• Pulmonary hypertension (elevated lung artery pressure, straining the right side of the heart)
• Kidney failure (fluid overload)

Symptoms

Heart failure typically develops gradually. Early in the disease, the heart compensates through a series of changes — the heart muscle enlarges, beats faster, and hormonal signals cause the kidneys to retain fluid. These adaptations temporarily maintain output but ultimately worsen the condition.

Common symptoms include:

• Shortness of breath (dyspnoea) — initially on exertion, later at rest; lying flat often worsens it (orthopnoea)
• Waking at night breathless (paroxysmal nocturnal dyspnoea)
• Fatigue and weakness — reduced cardiac output means muscles receive less oxygen
• Ankle, leg, and foot swelling (oedema) — excess fluid accumulates in the tissues
• Rapid or irregular heartbeat
• Persistent cough or wheezing, sometimes producing pink-tinged mucus
• Reduced ability to exercise
• Sudden weight gain from fluid retention (more than 1–2 kg in 24–48 hours is a warning sign)
• Nausea and abdominal swelling — when fluid backs up into the liver and digestive tract (right heart failure)
• Reduced urination during the day, with increased frequency at night (as the body reabsorbs fluid when lying down)

New York Heart Association (NYHA) Classification

Class	Description
I	No symptoms with ordinary activity
II	Slight limitation; symptoms with moderate exertion
III	Marked limitation; symptoms with minimal activity
IV	Symptoms at rest; unable to carry on any activity without discomfort

Diagnosis

Echocardiogram (Cardiac Ultrasound)

The cornerstone investigation. It visualises the heart in real time, measures the ejection fraction, assesses valve function, and identifies structural abnormalities. Echocardiography helps characterise heart function and filling pressures. Its findings are interpreted alongside symptoms, examination and other tests; ejection fraction alone does not establish or exclude heart failure.

Additional Investigations

• BNP / NT-proBNP blood test — elevated levels of these hormone markers strongly suggest heart failure; useful for confirming the diagnosis and monitoring response to treatment
• Electrocardiogram (ECG) — detects arrhythmias and signs of past heart attack
• Chest X-ray — reveals an enlarged heart shadow and fluid in the lung fields
• Blood tests — full blood count, kidney and liver function, thyroid hormones, iron studies
• Cardiac MRI — provides precise imaging of heart muscle damage and inflammation
• Coronary angiogram — where coronary artery disease is suspected as the underlying cause

Treatment

Heart failure requires long-term, multi-modal management. The goals are to relieve symptoms, slow disease progression, reduce hospitalisation, and prolong life.

Medications

The medicines below have different indications. The regimen depends on the heart-failure type, kidney function, blood pressure and other conditions; not every medicine is appropriate for every person.

Drug Class	Examples	How They Help
ACE inhibitors / ARBs	Ramipril, Losartan	Reduce workload; slow progression
Beta-blockers	Carvedilol, Bisoprolol	Slow heart rate; improve survival
SGLT-2 inhibitors	Empagliflozin, Dapagliflozin	Reduce hospitalisation; kidney protection
Loop diuretics	Furosemide	Remove excess fluid; relieve congestion
Mineralocorticoid antagonists	Spironolactone, Eplerenone	Reduce fluid; improve survival in HFrEF
Sacubitril/valsartan (ARNI)	Entresto	Superior to ACE inhibitors in HFrEF

Devices and Procedures

• Cardiac resynchronisation therapy (CRT) — a specialised pacemaker that coordinates the two ventricles, improving pump efficiency
• Implantable cardioverter-defibrillator (ICD) — can reduce the risk of sudden cardiac death from dangerous ventricular arrhythmias in appropriately selected patients; it does not prevent every cause of death
• Heart valve repair or replacement — if valve disease is the underlying cause
• Coronary artery bypass grafting (CABG) or PCI — if coronary artery disease is contributing
• Ventricular assist device (VAD) — a mechanical pump implanted to support the failing heart, used as a bridge to transplant or long-term therapy
• Heart transplantation — an option for selected people with advanced heart failure despite other treatment, following specialist assessment of eligibility; this is not a promise of transplant access

Lifestyle Modifications

• Salt intake — review your usual intake with the heart-failure team. NICE does not advise routine sodium restriction for everyone with heart failure; people consuming excessive salt may need to reduce it
• Fluid management — follow an individual plan. Fluid restriction may be appropriate in selected circumstances, such as dilutional hyponatraemia, but is not routine for everyone. Review any prescribed limit with the team rather than changing it yourself
• Daily weight monitoring — rapid gain signals fluid retention and prompts early intervention
• Exercise — supervised cardiac rehabilitation improves functional capacity and quality of life
• Avoiding alcohol — alcohol directly depresses cardiac muscle function
• Stopping smoking — reduces further coronary damage and hospitalisation

Heart Failure Management in China

For planned heart-failure care in China, ask the receiving team to confirm the indicated investigations and available services:

• Diagnostic work-up: echocardiogram, BNP, cardiac MRI, 24-hour Holter monitoring and full metabolic panel
• Device assessment (CRT, ICD): confirm clinical eligibility, the team’s relevant experience and follow-up arrangements
• Valve procedures — ask whether a catheter-based or surgical approach is appropriate and available for the specific valve problem
• Advanced heart-failure assessment — discuss available options and eligibility directly with the specialist team; no organ availability, transplant eligibility or waiting time is promised
• Language and coordination support — confirm the language, documents, visits and follow-up included in the agreed PriumCare service scope

If you or a family member is living with heart failure and seeking a specialist assessment or second opinion, contact a PriumCare care navigator to arrange an appointment.

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Sources and editorial correction

Background source: MSD Manual Professional: Chronic Heart Failure, by Nowell M. Fine, MD, SM, peer reviewed by Jonathan G. Howlett, MD. The source page lists a full review in October 2025 and an update in July 2026. Those credits and dates belong to the MSD source, not to authorship or clinical review of this PriumCare article.

• NICE NG106: diagnosis, treatment and salt/fluid advice.
• AHA: types of heart failure.
• AHA/ACC/HFSA heart-failure guideline.

Editorial source correction: 25 October 2026. This targeted check addressed classification, salt and fluid advice, ICD wording, service assertions and source attribution. It is not a clinical review of the whole article. No named medical reviewer of this PriumCare article is claimed. Original publication date is retained.