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.
On the other hand, your blood pressure could be 120/80 and still be considered dangerous low blood pressure if your body requires a higher blood pressure than this to perfuse your tissues. A sudden drop in blood pressure when standing (orthostatic hypotension) can be very dangerous if you lose consciousness and fall.