), ruptured aortic aneurysm, superior mesenteric artery syndrome, etc. Severe dehydration
Third spacing, e.g. malignant pleural effusion, ascites, severe peripheral oedema due to kidney failure
Rapid fluid shift due to dialysis
Cardiogenic shock
Myocardial infarction
Severe cardiac arrhythmia, e.g. ventricular fibrillation, sea water poisoning
Failed heart transplant or artificial heart; in those with cardiovascular disease who are just being treated with medical therapy or oxygen, pacing, cardioversion, or defibrillation using an implantable cardioverter-defibrillator, or else implantation of an intra-aortic balloon pump, or a unilateral or bilateral ventricular assist device, may help matters, as could the use of stenting and/or coronary artery bypass surgery and/or the removal of atherosclerotic plaques. Eventually, a heart transplant or artificial heart may be needed, and these can be replaced when they are no longer performing as well as they did. If necessary, while waiting for a transplant or device, extracorporeal membrane oxygenation (ECMO) or mechanical ventilation using a ventilator, or other less invasive methods, can be used to help compensate. If other systems get impaired, renal dialysis, liver dialysis, and artificial nutrition and hydration (including total or partial parenteral nutrition) can also be used. Congenital heart defects
Obstructive shock
Pulmonary embolism
Cardiac tamponade
Aortic dissection
Tension pneumothorax
Hypertrophic cardiomyopathy
Constrictive pericarditis
Distributive shock
Septic shock
Anaphylactic shock
Acute pancreatitis
Hypotension due to medications
Intoxicative inhalants
Combined
Dengue fever

Effects
The effects of a circulatory collapse vary based on the type of collapse it is.
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregnancy can have one or more gestations at the same time, for example in a multiple birth.The time interval of a gestation is called the gestation period. In obstetrics, gestational age refers to the time since the onset of the last menses, which on average is fertilization age plus two weeks. Mammals
In mammals, pregnancy begins when a zygote (fertilized ovum) implants in the females uterus and ends once the fetus leaves the uterus during labor or an abortion (whether induced or spontaneous). Humans
In humans, pregnancy can be defined clinically or biochemically. Clinically, pregnancy starts from the mothers last missed period. Biochemically, pregnancy starts when a womans human chorionic gonadotropin (hCG) levels rise above 25 mIU/mL.Human pregnancy can be divided into three trimesters, each approximately three months long: the first, second, and third trimester. The first trimester is from the last menstrual period through the 13th week, the second trimester is 14th–28/29th week, and the third trimester is 29/30th–42nd week. Birth normally occurs at a gestational age of about 40 weeks, though it is common for births to occur from 37 to 42 weeks.