Editing Blood vessel (section)

== Disease ==
{{Main|Vascular disease}}

Blood vessels play a huge role in virtually every medical condition. [[Cancer]], for example, cannot progress unless the tumor causes [[angiogenesis]] (formation of new blood vessels) to supply the malignant cells' metabolic demand.<ref>{{cite journal | vauthors = Nishida N, Yano H, Nishida T, Kamura T, Kojiro M | title = Angiogenesis in cancer | journal = Vascular Health and Risk Management | volume = 2 | issue = 3 | pages = 213–219 | date = September 2006 | pmid = 17326328 | pmc = 1993983 | doi = 10.2147/vhrm.2006.2.3.213 | doi-access = free }}</ref> [[Atherosclerosis]] represents around 85% of all deaths from [[Cardiovascular disease|cardiovascular diseases]] due to the buildup of [[Atheroma|plaque]].<ref>{{Cite journal |date=2023 |title=World Heart Report 2023 |url=https://world-heart-federation.org/wp-content/uploads/World-Heart-Report-2023.pdf |journal=World Heart Federation |publication-place=Geneva, Switzerland |page=5}}</ref> [[Coronary artery disease]] that often follows after atherosclerosis can cause [[Myocardial infarction|heart attacks]] or [[cardiac arrest]], resulting in 370,000 worldwide deaths in 2022.<ref>{{Cite web |last=CDC |date=2024-10-24 |title=Heart Disease Facts |url=https://www.cdc.gov/heart-disease/data-research/facts-stats/index.html |access-date=2024-10-30 |website=Heart Disease |language=en-us}}</ref> In 2019, around 17.9 million people died from cardiovascular diseases. Of these deaths, around 85% of them were due to heart attack and stroke.<ref>{{Cite web |title=Cardiovascular diseases (CVDs) |url=https://www.who.int/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds) |access-date=2024-10-30 |website=World Health Organization |language=en}}</ref>

Blood vessel permeability is increased in [[inflammation]]. Damage, due to [[Physical trauma|trauma]] or spontaneously, may lead to [[hemorrhage]] due to mechanical damage to the vessel [[endothelium]]. In contrast, occlusion of the blood vessel by [[Atheroma|atherosclerotic plaque]], an [[embolism|embolised]] [[blood clot]] or a [[foreign body]] leads to downstream [[ischemia]] (insufficient blood supply) and possibly [[infarction]] ([[necrosis]] due to [[Ischemia|lack of blood supply]]). Vessel occlusion tends to be a positive feedback system; an occluded vessel creates [[Eddy (fluid dynamics)|eddies]] in the normally [[laminar flow]] or [[plug flow]] blood currents. These eddies create abnormal fluid velocity gradients which push blood elements, such as cholesterol or [[chylomicron]] bodies, to the endothelium. These deposit onto the arterial walls which are already partially occluded and build upon the blockage.<ref>{{cite book | vauthors = Gidaspow D |title=Multiphase flow and fluidization : continuum and kinetic theory descriptions |date=1994 |publisher=Academic Press |location=Boston |isbn=978-0-12-282470-8}}</ref>

The most common disease of the blood vessels is [[hypertension]] or high blood pressure. This is caused by an increase in the pressure of the blood flowing through the vessels. Hypertension can lead to heart failure and stroke. Aspirin helps prevent blood clots and can also help limit inflammation.<ref>{{cite web|url=https://www.mercyhealth.org/services/heart/heart-disease/blood-vessels/ | archive-url = https://web.archive.org/web/20161018074232/https://www.mercyhealth.org/services/heart/heart-disease/blood-vessels/ | archive-date = 18 October 2016 |title=Blood Vessel Diseases – Mercy Health System|website=www.mercyhealth.org}}</ref> [[Vasculitis]] is inflammation of the vessel wall due to [[autoimmune disease]] or [[infection]].