Editing Lung (section)

===Blood-supply changes===
[[File:InfarctPandLbasilarsegmentsPE.PNG|thumb|[[Infarction|Tissue death]] of the lung due to a [[pulmonary embolism]]]]
<!-- Blood supply -->A [[pulmonary embolism]] is a blood clot that becomes lodged in the [[pulmonary arteries]]. The majority of emboli arise because of [[deep vein thrombosis]] in the legs. Pulmonary emboli may be investigated using a [[ventilation/perfusion scan]], [[CT pulmonary angiography|a CT scan of the arteries of the lung]], or blood tests such as the [[D-dimer]].<ref name=DAVIDSONS2014 /> [[Pulmonary hypertension]] describes an increased pressure at the beginning of the [[pulmonary artery]] that has a large number of differing causes.<ref name=DAVIDSONS2014 /> Other rarer conditions may also affect the blood supply of the lung, such as [[granulomatosis with polyangiitis]], which causes inflammation of the small blood vessels of the lungs and kidneys.<ref name=DAVIDSONS2014 />

A [[pulmonary contusion|lung contusion]] is a bruise caused by chest trauma. It results in hemorrhage of the alveoli causing a build-up of fluid which can impair breathing, and this can be either mild or severe.
<!-- Intrapleural collections -->The function of the lungs can also be affected by compression from fluid in the pleural cavity [[pleural effusion]], or other substances such as air ([[pneumothorax]]), blood ([[hemothorax]]), or rarer causes. These may be investigated using a [[chest X-ray]] or [[CT scan]], and may require the insertion of a [[surgical drain]] until the underlying cause is identified and treated.<ref name=DAVIDSONS2014>{{cite book|editor1=Brian R. Walker|editor2=Nicki R. Colledge|editor3=Stuart H. Ralston|editor4=Ian D. Penman|others=Illustrations by Robert Britton|title=Davidson's principles and practice of medicine|date=2014|publisher=Churchill Livingstone/Elsevier |isbn=978-0-7020-5035-0|edition=22nd}}</ref>