heart and blood vessel disorders
Low Blood Pressure
Causes of Low Blood Pressure
Low blood pressure typically results from one or more of the following: Dilation of small arteries (arterioles) Certain heart disorders Too little blood volume Dilation of arteriolescan be caused by Toxins produced by bacteria during certain severe bacterial infections ( Sepsis and Septic Shock , Certain drugs Spinal cord injuries, in which the nerves that cause the arterioles to constrict are impaired Allergic reactions ( Anaphylactic Reactions ) Certain endocrine disorders, such as Adrenal Insufficiency None Variousheart disordersthat impair the heart's pumping ability and reduce cardiac output include A heart attack ( Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina) ) A Overview of Heart Valve Disorders None An extremely rapid heartbeat ( Paroxysmal Supraventricular Tachycardia (SVT, PSVT) ) A very slow heartbeat ( Sinus Node Dysfunction ) An abnormal heart rhythm ( Overview of Abnormal Heart Rhythms ) Too little blood volumein the body may be caused by Dehydration Bleeding A kidney disorder Low blood pressure also occurs when the nerves that conduct signals between the brain and the heart and blood vessels are impaired by neurologic disorders called Autonomic Neuropathies . When a person quickly moves from a sitting position to a standing position, blood pressure in the blood vessels to the brain decreases, resulting in a temporary sensation of light-headedness or faintness. This is called Dizziness or Light-Headedness When Standing Up . It can be more pronounced in people who are dehydrated or warm (such as when emerging from a hot bath), have certain illnesses, or have been lying down or sitting for prolonged periods of time. Orthostatic hypotension can even cause people to faint. In most people, the body quickly acts to increase blood pressure and prevent the person from fainting. 