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OI/POTS (Orthostatic Intolerance/Postural Orthostatic Tachycardia Syndrome)

Orthostatic intolerance (OI) is a broad classification referring to exaggerated blood pressure and/or heart rate responses that occur when standing up (and sometimes sitting up).


Orthostatic symptoms can include fatigue, nausea, light-headedness, heart palpitations, sweating, and sometimes fainting (syncope).

One type of orthostatic issue, called POTS (postural orthostatic tachycardia syndrome), is the feedback loop that leads to an increased heart rate of 130 bpm (beats per minute) or more upon standing.


POTS UK suggests 27% of people with ME/CFS and 12% of people with Long-COVID have a POTS diagnosis, and it is expected that the actual prevalence of patients with POTS or OI may be as high as 70% for ME and 61% for Long-COVID.

OI/POTS is so common in the patient population that most diagnostic criteria (including the Canadian Clinical Working Case Definition) include orthostatic symptoms.

Although Pacing, and learning to move from lying to sitting/standing carefully, are the main ways to manage OI/POTS, there are a few key dietary approaches that are proven to decrease orthostatic symptoms in some patients (thank you to for much of the following detail):


One of the biggest problems in POTS is the inability to tolerate standing, due to blood pressure dropping and heart rate increasing.


Increasing fluid intake can help with these symptoms:

  • Hydrating can include all fluids, including soups, not just water. 

  • Be aware that anything including caffeine is a diuretic (meaning it will decrease your body fluid levels) and should be avoided for most patients.

  • Aim for more than 2 liters of water per day, or to maintain clear urine.

  • When you have strong symptoms of dizziness when standing, there is some evidence that drinking about 2 glasses of water immediately may help for some people.

Salt Intake

A high salt diet increases plasma volume, decreases plasma norepinephrine, and reduces orthostatic tachycardia, all of which help with the symptoms of POTS. Most experts recommend increasing your salt intake:

  • Increase dietary salt by around 2-4g/day.  

  • Particularly symptomatic patients may benefit from an increase of as much as 6-8g sodium/day if recommended by a doctor. 

  • Try to increase your salt intake through your diet. If you cannot, you may add salt tablets, but add these slowly as some people get an upset stomach.

Your best bet is adding table salt to your meals! But below are some other high sodium (salt) foods (in all cases, check the label to be sure and do not accidentally purchase the “low salt” or “low sodium” varieties!):

  • Cured, salted, smoked, canned meats and fish; sausages; shrimp and seafoods

  • Salted nuts

  • Canned beans, legumes

  • Feta, parmesan, cottage and blue cheese

  • Pizzas, fast food (but, if applicable for you, limit these for other health reasons such as other additive, fat and overall calories)

  • Processed cheeses (but these may have additional additives you may want to avoid)

  • Commercial mixed spices, dried parmesan cheese, most breading mixes

  • Most commercial cereals (check the label)

  • Many crackers, cookies, pastries and cakes

  • Salty snack foods like chips (there may be other health reasons to limit these)

  • Canned vegetable juice; electrolyte replacement drinks like Gatorade or Powerade

  • Canned vegetables, sauerkraut, pickled vegetables, pickles, relishes, olives

  • Regular canned soups/broths, dried soup mixtures, instant soups, bouillon cubes or powder, commercial meat extracts

  • Commercial salad dressing, vegetable dips, and gravy bases

  • Ketchup, Mustard, Soy sauce, Chili sauce

  • Baking soda, baking powder, cream of tartar, meat tenderizers, seasoned salt, sea salt, regular salt, MSG

  • There are even some fruits and vegetables that have higher sodium content. Apples, guavas, avocado, papaya, mango, carambola, pineapple, banana, melons, and pears contain natural sodium ranging between 1-8 mg per 100 grams. Celery, spinach, carrots and beets are also rich in sodium.

Lower Carbs and Smaller Meals

When we eat, there is increased blood flow to the digestive system. For POTS patients, this can lead to worsening of their orthostatic symptoms. When a large meal is eaten, the effect is even greater. See which of these recommendations work for you:

  • Avoid large meals.

  • Avoid eating very fast.

  • Eat several smaller meals throughout the day (many ME/CFS and Long-COVID patients report that this also helps to manage energy levels throughout the day).

  • There is evidence that the higher the carbohydrate content of a meal, the greater the lowering of blood pressure in patients with orthostatic symptoms. Blood pressure is higher (a good thing for people with POTS!) when carbohydrate content of meals is limited.

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