What is orthostatic intolerance?
Orthostatic intolerance (OI) means symptoms get worse when you’re upright (standing, or even sitting) and improve when you lie down. It’s the most commonly missed treatable part of ME/CFS.
Symptoms can include:
- lightheadedness or dizziness
- brain fog that gets worse when upright
- a racing or pounding heart
- nausea
- blurred or greying vision
- shakiness, sweating
- blotchy, purple or mottled legs when standing
- needing to sit, crouch or lie down, or fainting
POTS (postural orthostatic tachycardia syndrome) is one type: the heart rate rises by 30 or more beats per minute within 10 minutes of standing, without a big drop in blood pressure.
The home “lean test” (NASA 10-minute lean test)
You can do a version of this at home. Do it with someone else there in case you feel faint, and stop if you feel unwell.
- Do it in the morning, before caffeine.
- Lie flat for 10 minutes. Record your heart rate, and blood pressure if you have a cuff.
- Stand and lean your upper back against a wall with your heels about 15 cm out from the wall. Try not to move.
- Record your heart rate every minute for 10 minutes (and blood pressure at 2, 5 and 10 minutes if you can). Note any symptoms: lightheadedness, nausea, vision changes, mottled legs.
- A positive result is a sustained heart rate rise of 30+ bpm, or not being able to finish the 10 minutes.
- Write the numbers down and take them to your GP.
Managing it
Talk to your doctor before starting any of these. Salt in particular isn’t right for everyone.
| What | Details |
|---|---|
| Fluids | 2–3 litres a day |
| Salt | 2–3 g of extra sodium a day. Many electrolyte powders contain little sodium, so check the label. Higher-sodium products or salt tablets may be needed. Only if OI is confirmed. Without it, extra salt just raises blood pressure. |
| Compression | Waist-high compression garments. 20–30 mmHg is the usual starting strength. Talk to your doctor before going to 30–40 mmHg. |
| Bed | Raise the head of the bed slightly |
| Everyday tricks | Sit to shower and to do tasks; avoid standing still for long; cross your legs or clench your calves when you must stand; avoid heat and large carb-heavy meals; get up slowly |
| Medications (prescribed) | Options include pyridostigmine, fludrocortisone and ivabradine. See the notes below. |
| Referral | Cardiology or an autonomic clinic |
Notes on medications:
- Pyridostigmine has ME/CFS-specific data: a placebo-controlled trial found it improved how the heart and circulation respond to exercise. RCT See Medications.
- Ivabradine lowered heart rate but did not improve symptoms in the large RECOVER-AUTONOMIC Long COVID trial (381 patients). Adjacent field
Choosing compression garments
Why waist-high? Much of the problem in POTS is blood pooling in the abdomen and pelvis. Knee- or thigh-high stockings don’t address that.
Tips:
- Comfort: waist-high garments can be very tight in the groin. The medical term to search for is “open crotch”. It’s a standard medical option.
- Alternative: thigh-highs (some attach at the waist or have silicone top bands) avoid groin pressure but give no abdominal compression. They can be paired with an abdominal binder.
- Sizing: measure in the morning before any swelling: ankle, calf, upper thigh, and floor-to-buttock length. Or get fitted at a pharmacy or compression clinic.
- Putting them on: they snag easily. Rubber donning gloves help a lot.
- Brands: Juzo, Jobst, Sigvaris and Bauerfeind are all medical-grade. Australian stockists include Compression Stockings Online, Bodyment and BrightLife Direct.
- Cost (Australia): with private health extras cover, a prescription or fitting from a physio or GP may make them claimable.
Why this matters
Reduced blood flow to the brain when upright is closely linked to brain fog. For many people, treating OI is one of the few things that makes a clear, practical difference.