Cardiovascular · Topic 47 of 48
POTS & Orthostatic Hypotension
Cardiovascular · orthostatic intolerance
POTS & Orthostatic Hypotension
On standing, orthostatic hypotension drops the BP ≥ 20/10 mmHg; POTS raises the heart rate ≥ 30 bpm without a BP drop.
Key numbers
Orthostatic hypotension: BP drop ≥ 20/10≥ 20/10 mmHg in 3 min
POTS: heart rate rise ≥ 30 bpmHR ↑ ≥ 30 bpm
01 · Defined byOrthostatic hypotension: BP drop ≥ 20/10
Orthostatic hypotension = a fall in systolic BP of 20 mmHg or more, or diastolic BP of 10 mmHg or more, within 3 minutes of standing.
02 · Defined byPOTS: heart rate rise ≥ 30 bpm
POTS = sustained heart rate rise of 30 bpm or more (40 or more at age 12–19) within 10 minutes upright, without orthostatic hypotension, with orthostatic symptoms for at least 3 months.
03 · CauseAcute OH: volume loss, drugs, bed rest
The most common causes of acute orthostatic hypotension are hypovolemia, medications and prolonged bed rest; chronic orthostatic hypotension comes from aging, medications and autonomic dysfunction.
01
Causes & risk factors
Why it happensReview alpha-blockers, nitrates, diuretics, antipsychoticsReview the medication list: alpha-blockers (terazosin, doxazosin), nitrates, calcium channel blockers, diuretics, clonidine, tricyclics, antipsychotics, levodopa and alcohol all cause orthostatic hypotension; reduce or stop the culprit to confirm it.
Neurogenic OH: Parkinson, MSA, neuropathyChronic neurogenic orthostatic hypotension points to Parkinson disease, multiple system atrophy, pure autonomic failure or a diabetic, alcohol-related or amyloid neuropathy; look for constipation, urinary retention, anhidrosis and erectile dysfunction.
02
Presentation
What you'll seeNo heart-rate rise suggests autonomic failureOrthostatic hypotension with a heart-rate rise under 10 bpm suggests autonomic impairment (neurogenic); a rise above 30 bpm or to over 100 bpm suggests hypovolemia, or POTS if BP holds.
03
Management
OrdersCheck BP and heart rate supine, then standing must knowMeasure BP and heart rate after 5 minutes supine and again at 1 and 3 minutes of standing (sitting if the patient cannot stand); for POTS, keep recording up to 10 minutes.
Rise slowly, hydrate, compress, raise bed headFirst-line orthostatic hypotension care: rise slowly, drink adequate fluids, limit alcohol, wear waist-high compression, sleep with the head of the bed raised, and add salt 6–10 g/day if there is no heart failure or hypertension.
Fludrocortisone 0.1 mg expands plasma volumeFludrocortisone, starting at 0.1 mg daily, retains sodium and expands plasma volume (needs adequate salt intake); monitor for hypokalemia, edema, supine hypertension and heart failure.
Midodrine by day, never near bedtimeMidodrine, an alpha-1 agonist, is dosed in daytime hours (usual 10 mg three times daily); give the last dose at least 4 hours before bedtime because of its boxed warning for supine hypertension.
Droxidopa for neurogenic orthostatic hypotensionDroxidopa, a norepinephrine precursor, is FDA-approved for symptomatic neurogenic orthostatic hypotension (Parkinson disease, multiple system atrophy, pure autonomic failure); its boxed warning is supine hypertension — check BP with the head of the bed raised.
POTS: 3 L water, salt, compression, exerciseStart POTS treatment without drugs: about 3 L of water a day, liberal salt, waist-high or abdominal compression garments, and a graded recumbent aerobic exercise program (patients may feel worse for the first month).
Low-dose propranolol for POTS tachycardiaWhen standing tachycardia stays high, give low-dose propranolol 10–20 mg up to 4 times daily; ivabradine 2.5–7.5 mg twice daily is an alternative heart-rate reducer.
Other POTS drugs: midodrine, fludrocortisone, pyridostigmineOther POTS options: midodrine 2.5–15 mg three times daily (helps when BP is low), fludrocortisone 0.1–0.2 mg daily (monitor potassium) and pyridostigmine 30–60 mg up to three times daily (causes diarrhea and cramping).
04
Orthostatic hypotension or POTS?
Commonly confused| BP on standing | SBP falls ≥ 20 or DBP ≥ 10 mmHg |
|---|---|
| Heart rate on standing | Rises (volume loss) or barely rises (< 10 bpm, autonomic failure) |
| Time window | Within 3 minutes of standing |
| Typical patient | Older adult, volume loss, drugs, bed rest, neuropathy |
| First-line treatment | Stop offending drugs, fluids, salt, compression |
05
Commonly confused
Tell apartExclude other causes of sinus tachycardia firstBefore calling it POTS, exclude dehydration, anemia, hyperthyroidism, offending drugs and inappropriate sinus tachycardia (resting heart rate ≥ 100 bpm or 24-hour mean > 90 bpm regardless of posture).
06
More detail
ReferenceShow 5 reference facts
POTS affects 0.1–1% of people, mostly adolescent girls and young women; it is associated with migraine, hypermobile Ehlers–Danlos syndrome, mast cell activation and onset after viral illness including COVID-19.
Tilt-table testing gives more consistent results than bedside orthostatics when autonomic dysfunction is suspected; ECG, electrolytes, creatinine and glucose are routine, and further tests follow the history.
Postprandial hypotension follows high-carbohydrate meals and is worsened by alcohol; smaller, lower-carbohydrate meals and avoiding sudden standing after eating prevent it.
Orthostatic hypotension affects about 15–20% of older adults, causes many unrecognized falls, and is associated with higher cardiovascular and all-cause mortality.
Red flags in orthostatic hypotension are heme-positive stool (GI bleeding) and an abnormal neurologic examination; hyperpigmentation suggests adrenal insufficiency.
Watch the heart rate as well as the BP: a BP drop with no heart-rate rise points to autonomic failure; a big heart-rate rise without a BP drop is POTS.
Sources · Merck Manual Professional — Orthostatic Hypotension · Raj SR et al. Diagnosis and management of postural orthostatic tachycardia syndrome. CMAJ 2022;194:E378–E385 · Midodrine hydrochloride tablets — prescribing information (DailyMed) · Northera (droxidopa) — prescribing information (DailyMed) · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).