Salt - Your New Friend

With OI, you and your body are in an unusual place. Most people are told to "watch your salt intake- keep it low". That's because it can increase the blood pressure (BP) and cause "high" blood pressure. High blood pressure is generally not desired because it can cause strokes and other things.


BUT - a person with orthostatic intolerance (OI) needs the salt - because it helps increase blood pressure and increase the volume of blood in the body!


In general, salt and water go together in the body. Salt is like a sponge. If you put a dry sponge near water, it soaks up the water. Salt "soaks up" water in the body too. The blood has salt in it and that helps keep water in the blood stream. Having enough blood volume so blood gets to your head keeps you from getting OI symptoms when you stand up.

People with OI have low blood volume. For people who had an event before the OI symptoms started, there was usually a period of bedrest, usually longer than a few days. During bedrest, the body decreases the volume of blood. It changes the message to the kidneys about salt and water. (Learn more about the effects of bedrest under Deconditioning.)

If bedrest lasts long enough, the body adjusts its internal message centers to that "lying down" becomes "normal". Keeping the body at low blood volume becomes the "normal".

Think of it like your TV, cable TV and your remote. To make cable work, you have to set the TV to Channel 3 and program your remote. If you change the TV channel to an other channel, it isn't recognized and you don't get any Cable TV. Everything has to get reprogrammed to work again. It's like that when you are on prolonged bedrest. Your body, especially the low blood pressure sensors get reprogrammed. They now think that lying down is "normal". They change all the messages they send out to your body when you stand up. The result - your blood drops to your feet when you stand up and you get dizzy .


When the volume of blood is low

The "normal" body reaction when the volume of blood is low - it holds on to more salt and water. A message is sent to the kidneys to tell them hold on to salt and water. This would increase the volume of blood.

With OI. There is a "dysfunction" or a miscommunication from your blood pressure sensor cells in your neck, the baroreceptor cells.

With OI, the baroreceptors have adjusted and now think that low blood volume is "normal". Your body doesn't send out the message to the kidneys to hold on to the salt and water and increase the blood volume.

If your body is not saving the salt and water, you have to help it! You have to take in more salt so your body will hold on to the water/liquid you take in. That's how you increase your blood volume.For more about orthostatic symptoms, amount of blood and the body's reactions, go to How the Body Works in Orthostatic Conditions

Some people with orthostatic intolerance (OI) have been able to control their OI symptoms with their salt and fluid intake.

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Why You Need to Raise the Head of Your Bed - and How Much


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Author: Kay E. Jewell, MD
Page Last Updated: September 13, 2012