Resistant hypertension: when blood pressure won't budge

If you're taking three or more blood pressure medications (including a diuretic) and your BP is still above goal—or you need four or more meds to control it—you may have resistant hypertension.

This is frustrating, but it's also a signal to dig deeper.

TL;DR

• Resistant HTN = BP above goal despite ≥3 meds (including a diuretic), or needing ≥4 meds to control it
• Common culprits: medication non-adherence, white-coat effect, secondary causes (sleep apnea, kidney disease, aldosterone excess), lifestyle factors
• Workup: confirm BP accuracy, review meds, screen for secondary causes
• Treatment: optimize existing meds, address secondary causes, consider specialist referral

What is resistant hypertension?

Resistant hypertension is defined as:

• BP above goal despite ≥3 antihypertensive medications (one should be a diuretic), OR
• BP at goal but requiring ≥4 medications

This is different from "uncontrolled hypertension" (which may just need better adherence or dose adjustments).

Why does it happen?

Common reasons include:

1. Medication issues

• Non-adherence (most common—often unintentional)
• Suboptimal dosing or drug selection
• Drug interactions (NSAIDs, decongestants, etc.)

2. White-coat effect

• BP is high in the office but normal at home
• Home BP monitoring or 24-hour ambulatory monitoring can clarify this

3. Secondary causes

• Obstructive sleep apnea (very common, often missed)
• Primary aldosteronism (excess aldosterone from adrenal glands)
• Chronic kidney disease
• Renal artery stenosis (narrowing of kidney arteries)
• Thyroid disorders
• Coarctation of the aorta (rare, usually diagnosed earlier in life)

4. Lifestyle factors

• High sodium intake
• Excess alcohol
• Obesity
• Physical inactivity

How do we approach it?

The workup usually includes:

1. Confirm BP accuracy

   • Proper cuff size, correct technique
   • Home BP monitoring or ambulatory monitoring

2. Review medications

   • Are you taking them as prescribed?
   • Are doses optimized?
   • Are there interfering drugs (NSAIDs, steroids, decongestants)?

3. Screen for secondary causes

   • Sleep study if sleep apnea suspected
   • Aldosterone/renin ratio if primary aldosteronism suspected
   • Kidney function tests, renal artery imaging if indicated
   • Thyroid function

4. Optimize lifestyle

   • Sodium restriction (<2g/day for most)
   • Weight loss if overweight
   • Limit alcohol
   • Regular physical activity

Treatment strategies

• Optimize existing meds: ensure you're on appropriate doses of complementary drug classes
• Add a mineralocorticoid receptor antagonist (spironolactone or eplerenone) if not already on one
• Treat secondary causes: CPAP for sleep apnea, surgery/ablation for primary aldosteronism, etc.
• Consider specialist referral if BP remains uncontrolled despite maximal medical therapy

Practical next steps

• If you're on ≥3 BP meds and still above goal, ask about resistant hypertension workup
• Get a home BP monitor and track your readings
• Review your medication list with your doctor—including over-the-counter drugs
• Consider a sleep study if you snore, have daytime fatigue, or witnessed apneas

References (patient-friendly)

• 2017 ACC/AHA Hypertension Guideline (Circulation, 2018)
• 2018 AHA Scientific Statement on Resistant Hypertension (Hypertension, 2018)

Educational content only; not medical advice.