What is the most common cause of right heart failure?

The right side of the heart normally sends blood through the lungs to collect oxygen. When the left side cannot receive or pump blood efficiently, pressure can build behind it and pass back into the lung blood vessels. The right ventricle then has to pump against greater resistance and may gradually weaken.

Right-sided failure can also have other causes, including long-standing lung disease, pulmonary blood-vessel problems, or a valve disorder. A person may develop fluid retention, swollen ankles, abdominal fullness, tiredness, or breathlessness. These features overlap with other conditions, so symptoms alone cannot identify the cause.

Arrange a medical assessment if you have new swelling, increasing fatigue, breathlessness, or a known heart or lung condition. Assessment may include an examination, blood tests, an electrocardiogram, chest imaging, and an echocardiogram to assess heart structure and pumping.

Take prescribed heart or blood-pressure medicines as directed, keep follow-up appointments, and tell the clinician about changes in weight, ankle swelling, sleep, exercise tolerance, or urination. Do not start or stop diuretics or restrict fluids without personalised advice.

Seek emergency help for severe or rapidly worsening breathlessness, chest pain, fainting, confusion, blue or grey lips, or an inability to speak in full sentences. Sudden palpitations with weakness or collapse also need urgent assessment.

Contact a clinician promptly when swelling is steadily increasing, breathing becomes harder when lying down, or usual activities become noticeably more difficult. These changes can signal fluid accumulation or a change in heart rhythm or function.

Ask what is putting strain on the right side of your heart, whether the left side or lung circulation is involved, and which tests will clarify the cause. You can also ask how to monitor swelling and breathlessness, which medicines require review, and what symptoms should trigger same-day care.