Neuron Structure. Your brain is made of approximately 100 billion nerve cells, called neurons. Neurons have the amazing ability to gather and transmit electrochemical signals -- think of them like the gates and wires in a computer.
Most doctors will only consider chronically low blood pressure as dangerous if it causes noticeable signs and symptoms, such as: 1  Dizziness or lightheadedness. 2  Nausea. 3  Fainting (syncope)  Dehydration and unusual 1  thirst. Dehydration can sometimes cause blood pressure to drop.  Lack of 1  concentration. Blurred vision.  Cold, clammy, pale skin.
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 calledautonomic 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 lightheadedness or faintness.