Symptoms and Causes

What are the symptoms of heart failure?

Heart failure symptoms vary by person and may begin suddenly or develop gradually over weeks or months. The most common symptoms of heart failure are

• Shortness of breath.
• Fatigue and weakness.
• Swelling (legs, ankles, belly) due to fluid retention.
• Persistent cough or wheezing.
• Rapid or irregular heartbeat.
• Unusual weight gain from fluid.
• Reduced ability to exercise.
• Very rapid weight gain from fluid buildup.
• Loss of appetite, nausea, or difficulty concentrating.

Different types of heart failure?

Main types based on where the heart is affected.

• Left‑Sided Heart Failure: ​This is the most common form of heart failure. It happens when the left ventricle (the main pumping chamber) can’t effectively push oxygen‑rich blood out to the rest of the body. As a result, blood can back up into the lungs, which often leads to shortness of breath, coughing, and fatigue because your body isn’t getting enough oxygen.
• Right‑Sided Heart Failure: Right‑sided heart failure occurs when the right ventricle can’t pump blood well to the lungs. When this happens, blood backs up in the veins, returning blood to the heart. This typically causes swelling in the legs, ankles, and abdomen and can make you feel bloated or heavy.
• Biventricular Heart Failure: This type means both sides of the heart are struggling. It combines features of left- and right-sided failure, so a person might experience breathing problems from fluid in the lungs and fluid buildup in the body at the same time.
• Acute Heart Failure: Acute heart failure develops suddenly, often over hours or days. It can happen after a heart attack or a rapid change in heart function.
• Chronic Heart Failure: ​Chronic heart failure develops gradually over weeks, months, or years due to long‑term strain on the heart (like high blood pressure or coronary artery disease). Symptoms can be milder or manageable, and people often live with them for a long time while under medical care.

What causes heart failure?

Causes of heart failure include:

• Coronary Artery Disease (CAD): When the arteries that supply blood and oxygen to the heart become narrowed or blocked by plaque, the heart muscle doesn’t get enough oxygen. This weakens the heart and can lead to heart failure over time.
• Heart Attack: A heart attack permanently damages part of the heart muscle, forming scar tissue that can’t pump effectively. This reduces the heart’s ability to pump blood and may result in heart failure.
• High Blood Pressure (Hypertension): High blood pressure forces the heart to work harder to pump blood, gradually making the heart muscle thicker and weaker, which can cause heart failure.
• Cardiomyopathy (Heart Muscle Disease): This includes diseases where the heart muscle becomes too weak, stiff, enlarged, or damaged from genetic factors, infections, alcohol/drug use, or unknown reasons, reducing pumping ability.
• Heart Valve Problems: Faulty valves force the heart to work harder to circulate blood. Over time, this extra strain can weaken the heart and lead to failure.
• Arrhythmias (Irregular Heartbeat): Abnormal heart rhythms, whether too fast, slow, or irregular, reduce effective pumping and can contribute to heart failure.
• Congenital Heart Defects: Structural problems present from birth can make the heart less efficient, increasing the workload and risk of heart failure.
• Other Conditions: Several other long‑term health conditions can weaken the heart or make it work harder, increasing the chance of heart failure. These include diabetes, which harms blood vessels and the heart muscle; chronic lung diseases like COPD that reduce oxygen levels and strain the heart; thyroid disorders (both overactive and underactive) that disrupt heart rate and muscle function; and anemia, where low red blood cells force the heart to pump harder to deliver oxygen to the body.

Diagnosis of Heart Failure

Tests that may be done to diagnose heart failure may include:

• Chest X‑Ray: A quick image of your heart and lungs that can show if the heart is enlarged or if there’s fluid buildup in the lungs.
• Electrocardiogram (ECG / EKG): A painless test that records the heart’s electrical activity to check heart rate, rhythm, and signs of past heart damage.
• Echocardiogram (Echo): Ultrasound imaging of the beating heart that shows heart size, structure, valve function, and blood flow.
• Ejection Fraction Measurement: Although technically part of the echocardiogram, ejection fraction gets its own mention because it’s critical: it tells how well your heart is pumping. A lower percentage means your heart isn’t pumping as strongly as it should, which helps guide treatment plans
• Exercise or Stress Tests: During a stress test, you walk on a treadmill or pedal a stationary bike while your heart is monitored. This shows how well your heart works when it’s active, since some problems only show up during exertion. If you can’t exercise, medicines may be used to simulate the effect.
• CT Scan of the Heart: A cardiac CT scan uses X‑rays to create detailed cross‑sectional pictures of your heart. It helps doctors see the heart’s structure and blood vessels to identify abnormalities that might be contributing to heart failure.
• Heart MRI (Cardiac MRI): A cardiac MRI uses magnetic fields and radio waves to produce high‑resolution images of your heart’s tissues and chambers. It’s particularly useful when doctors need a very clear picture of heart structure and function.
• Coronary Angiogram: This is a more invasive test where a thin tube (catheter) is threaded through a blood vessel in your wrist or groin to your heart. A special dye is injected so X‑rays can reveal blockages or narrowing in the heart’s arteries, helping identify coronary artery disease as a cause of heart failure.
• Blood Tests: Blood tests involve drawing a small sample of your blood to check for signs of heart strain and other conditions that affect the heart. One key marker doctors look for is BNP (B‑type natriuretic peptide), a protein that rises when the heart is under stress. These tests also show how well your kidneys, liver, and electrolytes are functioning, since problems in these areas can influence heart failure.
• Myocardial Biopsy: In rare situations, doctors may remove a very small piece of heart muscle to examine it under a microscope. This can help diagnose specific muscle diseases that lead to heart failure, especially when other tests don’t give a clear answer.