Heart Failure: This is the most common cause of increased JVD. Heart failure, particularly right-sided heart failure, leads to fluid buildup in the body, causing increased pressure in the jugular veins, which manifests as JVD.

Chronic Obstructive Pulmonary Disease (COPD) Exacerbation: COPD can lead to increased pressure in the thoracic cavity, which in turn increases the pressure in the jugular veins.
Pulmonary Embolism: A blockage in one of the pulmonary arteries can increase the pressure in the right side of the heart, leading to increased JVD.
Pericardial Effusion: Fluid accumulation in the pericardial space can compress the heart, impeding its ability to fill with blood properly, and thus increasing the venous pressure.
Hypervolemia: Excess fluid in the body can lead to increased venous pressure, manifesting as JVD.

Cardiac Tamponade: Although less common, cardiac tamponade is a life-threatening condition where fluid accumulation in the pericardial sac compresses the heart, severely impairing its function. It requires immediate medical attention.
Pulmonary Hypertension: Elevated blood pressure in the pulmonary arteries can lead to right heart failure, presenting with increased JVD among other symptoms.
Constrictive Pericarditis: A condition where the pericardium becomes stiff and unable to stretch, restricting the heart's ability to fill with blood, which can mimic heart failure and present with increased JVD.

Superior Vena Cava Syndrome: Obstruction of the superior vena cava can cause increased pressure in the veins of the upper body, including the jugular veins.
Tricuspid Stenosis: A narrowing of the tricuspid valve, which can lead to increased pressure in the right atrium and jugular veins.
Cor Pulmonale: Right-sided heart failure caused by long-standing pulmonary disease, leading to increased JVD.
Budd-Chiari Syndrome: A rare condition caused by occlusion of the hepatic veins or the inferior vena cava, leading to liver enlargement and increased venous pressure, which can manifest as JVD.