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.
If your blood pressure is lower than 90/60, you have low blood pressure, or hypotension. You may feel lightheaded, weak, dizzy, or even faint. Low blood pressure can be caused by not drinking enough liquids (dehydration), blood loss, some medical conditions, or too much medication.