The MastAttack 107: The Layperson’s Guide to Mast Cell Diseases, Part 12

I have answered the 107 questions I have been asked most in the last four years. No jargon. No terminology. Just answers.

20. Why do a lot of mast cell patients get intravenous (IV) fluids?
• Use of IV fluids is becoming increasingly common for mast cell patients as word spreads that it helps with fatigue, overall energy, and general reactivity.
There have not been any studies showing that IV fluids work directly for mast cell disease. However, there have been papers demonstrating that it helps with deconditioning (when your body is out of shape from being sick), POTS (which a lot of mast cell patients have), and other chronic illnesses.
• A lot of chemicals that mast cells release can cause some of the liquid in your bloodstream to fall out through the walls of the bloodstream and become trapped in the tissues there. This phenomenon is called third spacing.
• The term “third spacing” is derived from the idea that fluids like blood or other fluids can be in one of three “spaces” in the body. One space is inside the cells, where cells can use it. Another space is right outside the cells, where cells can still use it. When fluids are stuck in a place that can’t be used by cells, and therefore is not useful to the body, it is said to be in a third space. So third spacing is when the fluids your body needs is stuck in the wrong place.
Third spacing is the cause of most types of swelling and edema.
• When you have fluid that should be in your bloodstream stuck in a third space, you are functionally dehydrated. This is important because bloodwork may not always show that you are truly dehydrated when you have a lower amount of third spacing but you will still have a lot of the symptoms of it.
IV fluids puts more fluids back into the blood to compensate for the fluids that get sucked out of the bloodstream and aren’t useful to the body. When this fluid is replaced, it helps stabilize blood pressure and heart rate. It also takes stress off many other cells so they calm down too, calming down mast cells.

For more detailed reading, please visit this post:

Third spacing

I also wrote a seven part series on third spacing and IV fluids. The first post is here.