Synonyms in a broader sense
Perfusion disorder
Epidemiology
The occurrence of circulatory disorders becomes more and more probable with increasing age. Up to the age of 45, only about 2% of the population suffer from a circulatory disorder, among the 60 to 70-year-olds about one in ten is affected by this clinical picture, with men becoming ill about 4 times as frequently as women of the same age. These data, however, only apply to the western world; in other countries, especially in developing countries, far fewer people are affected, mainly due to lifestyle and the associated risk factors (see below).
Causes
There are many causes for circulatory disorders, only the most important of which are described in more detail here. Among the causes are primarily the narrowing or occlusion of arteries, which can be caused by arteriosclerosis, vascular occlusion (embolism) or the formation of blood clots within the artery. Other causes are inflammation of blood vessels (vasculitis), cramps in the muscles of the blood vessels (vascular spasms), too low blood pressure (arterial hypotension) or sudden bleeding (for example cerebral haemorrhages).
The most common cause of a circulatory disorder is probably arteriosclerosis (such as calcified carotid arteries), which is a systemic disease. Various vessels can become calcified, e.g. the probability of arteriosclerosis increases with age. In the context of arteriosclerosis (literally translated: hardening of the connective tissue of the arteries), deposits occur on the inside of the vessels.
Initially, small injuries in the vessel wall are probably responsible for this. As a reaction to these injuries, the body switches on its defense system. This triggers a series of complicated biochemical processes that result in the deposition of blood cells, blood fats, connective tissue and, in some cases, calcium in the vessels.
These substances are often referred to as “plaques”. In principle, these deposits can occur anywhere in the arterial system. However, since flow conditions play a role in the formation of plaques, arteriosclerotic occlusions are preferably found where vessels branch out and the uniform flow is impeded.
As a rule, circulatory disorders do not develop immediately. The deposits grow more and more over time, whereupon the diameter of the arteries steadily decreases. The body therefore has a lot of time to react to the vascular changes.
As a result, on the one hand smaller blood vessels now mainly take over the blood supply, which previously played a subordinate role, and on the other hand so-called bypass circuits (collateral circulation) form around the affected areas. Therefore complaints often only show up when the arteriosclerosis has already advanced massively and the blood flow is extremely restricted. An embolism occurs when a vessel suddenly becomes blocked, namely when a blood clot, which may have formed at a completely different, more distant point in the vascular system, is carried away and becomes trapped in a usually smaller vessel, closing it. This embolism is usually triggered by a blood clot (thrombosis), but it can also be caused by the distension of tumor tissue, amniotic fluid or even air.
All articles in this series:
