<P> Superior vena cava obstruction refers to a partial or complete obstruction of the superior vena cava, typically in the context of cancer such as a cancer of the lung, metastatic cancer, or lymphoma . Obstruction can lead to enlarged veins in the head and neck, and may also cause breathlessness, cough, chest pain, and difficulty swallowing . Pemberton's sign may be positive . Tumours causing obstruction may be treated with chemotherapy and / or radiotherapy to reduce their effects, and corticosteroids may also be given . </P> <P> In tricuspid valve regurgitation, these pulsations are very strong . </P> <Ul> <Li> <P> Diagram showing completion of development of the parietal veins . </P> </Li> <Li> <P> Front view of heart and lungs . </P> </Li> <Li> <P> Heart seen from above . </P> </Li> <Li> <P> Superior vena cava </P> </Li> <Li> <P> Transverse section of thorax, showing relations of pulmonary artery . </P> </Li> <Li> <P> The arch of the aorta and its branches . </P> </Li> <Li> <P> The brachiocephalic veins, superior vena cava, inferior vena cava, azygos vein, and their tributaries . </P> </Li> </Ul> <Li> <P> Diagram showing completion of development of the parietal veins . </P> </Li>

Superior vena cava drains blood from the head and neck