What is hypotension? Hypotension is a condition where blood pressure in the arteries is lower than the normal threshold. Hypotension is difficult to detect because this disease sometimes does not cause low blood characteristics.Sometimes even low blood pressure is a good thing, because it is the goal to be achieved in keeping blood pressure under control. Being bad is because low blood pressure does not provide enough blood flow to the body's organs. In essence, all return to hypotensive symptoms complained by the patient.Blood pressure reading has two parts, namely, systolic pressure (upper number) and diastolic pressure (lower number). Normal blood pressure is between 90\/60 and 140\/90. People with hypotension have blood pressure below 90\/60 and are accompanied by symptoms of hypotension. Whereas if blood pressure is above 140\/90, then the person suffers from high blood pressure or hypertension.As is known, blood vessel walls are flexible walls, which means that the space in the arteries can be bigger or smaller. If the space is bigger, and the liquid is less then the pressure will drop. Meanwhile, if the space gets smaller the pressure will increase.Arteries have a layer of muscle in the wall that can contract and make the space in the blood vessels narrower but can also make the space in the blood vessels wider.These muscles are under the control of the autonomic nervous system, the body's automatic system that makes adjustments to changes in the body's condition to the environment. The autonomic nervous system has two paths that balance each other, namely:The sympathetic nervous system uses adrenaline (epinephrine) which causes muscles in the walls of blood vessels to contract (sympathetic tone). This nerve is located on the sympathetic trunk, which is a group of nerves that travel beside the spine.The parasympathetic nervous system uses acetylcholine to make the muscles in the walls of blood vessels relax through the vagus nerve.For example, when you stand up, blood vessels have to narrow and cause a slight increase in blood pressure that allows blood to travel uphill to the brain. Without this process, you can feel dizzy to cause fainting.Well , that's the meaning of hypotension. So, now you know what hypotension is , right ? Next see the causes, low blood characteristics to how to deal with low blood pressure.