Feeling lightheaded upon standing is a common characteristic of orthostatic intolerance. Orthostatic intolerance can be caused by many things, including a dysfunctional nervous system, viruses, low blood volume, and is associated with disorder such as Ehlers-Danlos syndrome (EDS) and Mast Cell Activation Disorder (MCAD).
*Check with doctor before trying any of the topics discussed, you may have other conditions that would make some of the ideas like increasing sodium a bad idea.
Introduction to POTS and Orthostatic Intolerance
Postural orthostatic tachycardia syndrome (POTS) is characterized by orthostatic intolerance due to dysautonomia. Dysautonomia is when the autonomic nervous system doesn’t function correctly. The autonomic nervous system is the part of the nervous system that cannot be controlled consciously (although that is not entirely true). When a person with POTS stands up, their heart rate rises more than 30 bpm above base line, or more than 120 bpm within 5-19 min of standing. Their blood pressure may or may not change. Once they are lying flat again, their heart rate returns to baseline. (R)
Persons with POTS get orthostatic hypotension, which is a decrease in blood pressure when standing.
Normally, when a person stands, the autonomic nervous system maintains blood pressure to ensure adequate blood circulation. A persons with POTS is unable to maintain healthy circulation, and when they stand, 0.5 to 1.0 L of blood can pool in the lower extremities. This means that the rest of the body, particularly the brain, doesn’t receive adequate circulation, and causes dizziness, lightheadedness, and even fainting. (R)
Symptoms of POTS generally occur abruptly, especially after a viral infection, immunization, pregnancy, or surgery. (R)
POTS is associated with Ehlers-Danlos syndrome (EDS) (R) and mast cell activation. (R) When mast cells degranulate, they release histamine, which is a vasodilator and can lead to increased orthostatic intolerance. (R)
Autoimmunity can also contribute to POTS. Some patients diagnosed with POTS have ganglionic acetylcholine receptor antibodies, as well as autoantibodies to cardiac membrane proteins and adrenergic receptor autoantibodies. (R)
- Light headedness
- Presyncope (almost fainting)
- Brain Fog
- Postprandial hypotension – low blood pressure after eating
- Lower back pain
- Neck and shoulder aches
- Cold hands and feet
- Joint hypermobility
- Chronic fatigue
- Neuropathic pain
- Early satiety
- Poor sleep
- Orthostatic headaches
- Cognitive dysfunction (brain fog)
These symptoms can be triggered by normal living tasks, such as eating, standing, showering, and walking short distances. (R)
Unfortunately, if doctors don’t specifically test for POTS using a tilt table test, no clinical signs are found, and patients are often diagnosed instead with anxiety disorder. (R)
The two primary forms of POTS are partial dysautonomic and hyperadrenergic. The partial dysautonomic form occurs from peripheral autonomic neuropathy. The hyperadrenergic form is usually familial, and is characterized by an increase in norepinephrine when standing. The increase in norepinephrine is caused by a decrease in norepinephrine clearance. (R)
Secondary forms of POTS are caused by other disorders, such as diabetes, joint hyper mobility syndrome, sarcoidosis, lupus, heavy metal poisoning, and chemotherapy. (R)
Some drugs can increase symptoms of POTS. Most of the drugs are aimed at vasodilation, and thus can decrease blood pressure.
Drugs that increase symptoms of POTS: (R)
- ACE inhibitors
- Calcium channel blockers
- Tricyclic antidepressants
Pharmacological treatment for POTS usually involves increasing vasoconstriction, limiting heart rate, and increasing blood volume. (R)
Renin-Angiotensin-Aldosterone System (RAAS)
Most people with POTS have decreased blood volume, and their bodies have a hard time adjusting to low blood volume (renin-aldosterone paradox). In a healthy person without POTS, when blood volume is low it stimulates increased renin, angiotensin, and aldosterone activity, which in turn increases vasoconstriction and sodium and water retention. Together, this increases blood volume levels back to normal and maintains adequate blood circulation and blood pressure. Persons with POTS and low blood volume tend to have low plasma renin and aldosterone levels, which makes sense. (R)
Interestingly, persons with POTS have been found to have increased levels of plasma Angiotensin II. (R)
Low blood volume stimulates increased renin, which converts angiotensinogen to angiotensin I. Angiotensin I is converted to Angiotensin II by Angiotensin converting enzyme (ACE). Angiotensin II then stimulates the secretion of aldosterone by binding to receptors on the adrenal gland (Angiotensin II type 1). Angiotensin II inhibits renin production, so it acts as a negative feedback loop.
Angiotensin II should increase aldosterone levels, but if there is something wrong with the Angiotensin II type 1 receptors on the adrenal glands, or a person is sodium loading, then aldosterone levels may not rise. If Angiotensin II levels are chronically elevated, the receptor responsiveness may diminish over time. (R)
When blood volume is low, renin and angiotensin II activity should increase to increase blood volume, but this doesn’t happen in some patients with POTS. Angiotensin II increases sodium and water retention by stimulating sodium reabsorption in the kidneys and by stimulating aldosterone secretion.
Aldosterone secretion is stimulated by angiotensin II, adrenocorticotropic hormone, and also by potassium and low sodium (hyponatremia). Another interesting finding is that sodium and potassium levels have been found to be similar in persons with POTS and persons without POTS. (R)
Natural Ways To Manage POTS
Avoid salt and fluid depletion, and increase salt and fluid intake if needed. 2 L of water and 3-5 g of salt are recommended each day. (R)
Watch your potassium intake. I think it’s a good idea to maintain adequate potassium intake, while still increasing sodium intake. To start, make sure your consuming enough sodium and water, as well as enough potassium. Slowly increase you water and sodium intake, and see if you feel better.
Water-bolus treatment can be used, which is consuming two 8-ounce glasses of water rapidly. This increases standing systolic blood pressure by roughly 20 mm Hg for 1-2 hours. (R)
This is a good technique to use before certain activities, such as standing for a while, exercising, or shopping trips. Be careful not to drink too much water though, and it might be a good idea to not sip water throughout the day if you water-bolus more than once. Drinking a couple glasses of water right away in the morning is a good idea to get the blood volume up a bit.
Get Better Sleep
Persons with POTS tend to sleep poorly, and have excessive fatigue. (R) Not getting quality sleep further exacerbates any illness.
Eat Smaller Meals
Eating smaller meals may help decrease the low blood pressure occurring after eating, because less blood is needed for digesting smaller meals compared to larger meals. (R)
Caffeine may help with symptoms of POTS, or it may worsen them. I think for most people they will know how it makes them feel. Caffeine is a diuretic, which could lead to a lower blood volume (hypovolemia) and worsen symptoms. (R)
However, caffeine also causes vasoconstriction, which could potentially help increase blood pressure and alleviate symptoms.
Thiamin – Vitamin B1 Deficiency
Thiamin deficiency (Wernick korsakoff syndrome) can cause orthostatic hypotension. (R) Be sure you are getting enough B1 in your diet, and every other vitamin and mineral.
Try a Low Histamine Diet
If you have histamine intolerance or Mast Cell Activation Disorder (MCAD), then it’s a good idea to try a low or relatively low histamine diet. (R)
Histamine is a vasodilator, which may lower blood pressure and contribute to orthostatic intolerance. (R)
Liposomal luteolin in olive fruit extract has been shown to improve brain fog in patients with mastocytosis. Luteolin is a mast cell stabilizer, antioxidant, and anti-inflammatory flavonoid. (R)
If you’ve got POTS and problems with mast cells, then luteolin and/or quercetin could potentially help.
Alcohol can be a trigger and often makes symptoms worse. (R) Avoid alcohol.
If standing for long periods of time or feeling faint, squeezing feet, leg and butt muscles can help prevent blood pooling. Also, moving the lower body will be better than just standing in one spot. (R)
Elevate Head During Sleep
Elevating the head during sleep is to help recondition the body to orthostatic stress. This can be done by placing 1 or 2 books under the mattress. (R)
Blood pooling in the lower extremities is an issue during upright and standing positions. Compression garments may help alleviate this. (R)
Exercise is used to expand blood volume, and recondition the muscles and increase venous return. (R)
Exercise and lower limb training can help pump blood and improve circulation. Intensity and duration should be increased gradually. (R)
Persons with pots often have a lower stroke volume. Exercise can help increase stroke volume, which is one reason why exercise improves both physical fitness and cardiovascular response in persons with POTS. Since many will be symptomatic during exercising, especially if just beginning an exercise program, it’s important to start with a very small amount of exercise. Both cardio and light strength training exercise are beneficial. (R)
If you can’t stand or exercise standing up, using a recumbent exercise bike might be a viable option. (R)
The vagus nerve could be a potential target for therapy for POTS.
The vagus nerve is a cranial nerve that is part of the parasympathetic nervous system, which is also known as the rest-and-digest system. The vagus nerve connects to the brain, heart, intestines, stomach, and many other organs.
The vagus nerve is part of the autonomic nervous system, which also helps to regulate blood pressure. (R)
The vagus nerve probably plays a large role in the pathophysiology of POTS, but it was difficult to find any substantial research on the direct correlation between the vagus nerve and POTS.
Gastroparesis is a common symptom in POTS, and gastroparesis is likely caused by damage to the vagus nerve, or a part of the signaling that occurs between the nerve and gut. (R)
Improving the function of the vagus nerve and the signals between it and organs could help alleviate symptoms of POTS.
Causing vibrations in the back of the throat/ears is thought to stimulate the vagus nerve. (R)
So to stimulate the vagus nerve, we just need to cause those vibrations.
Here are a few ways to stimulate the vagus nerve:
- “Om” chanting
- Singing loudly
*Before you try any of the topics discussed, check with your doctor or other professional health care provider to ensure that its safe, and so that you can be closely monitored.