How do I manage hypotension (low blood pressure)?

Management of Low Diastolic Pressure

For isolated low diastolic pressure without symptoms or orthostatic changes, no specific treatment is required; however, if symptomatic hypotension or orthostatic hypotension is present, begin with non-pharmacological measures including increased fluid intake (2-3 liters daily) and salt intake (6-9g daily), physical counter-maneuvers, and compression garments, reserving pharmacological therapy with midodrine or fludrocortisone for refractory cases. 1

Initial Assessment and Diagnosis

The first critical step is determining whether low diastolic pressure represents true pathological hypotension or is simply a benign finding:

• Measure blood pressure after 5 minutes of sitting/lying, then at 1 and 3 minutes after standing to identify orthostatic hypotension (defined as a drop in systolic BP >20 mmHg or diastolic BP >10 mmHg upon standing). 1

• Evaluate for symptoms including dizziness, syncope, headache, visual disturbances, fatigue, or altered mental status that would indicate clinically significant hypotension requiring intervention. 2, 1

• Assess for signs of inadequate organ perfusion including cool extremities, decreased urine output, or tachycardia, particularly if systolic BP is <80 mmHg, which represents severe hypotension requiring urgent intervention. 3

Identify and Address Reversible Causes

Before initiating specific hypotension treatment, systematically evaluate for correctable underlying causes:

• Review all medications as drug-induced hypotension is the most frequent cause, particularly diuretics, vasodilators, antihypertensives (ACE inhibitors, ARBs, calcium channel blockers), and beta-blockers. 1, 3

• Evaluate for volume depletion from inadequate fluid intake, excessive diuresis, or gastrointestinal losses. 1

• Screen for endocrine causes including adrenal insufficiency, hypothyroidism, or diabetes with autonomic neuropathy. 4

• Consider cardiac causes including heart failure, which commonly presents with hypotension and requires careful assessment of organ perfusion rather than relying solely on BP numbers. 3

Non-Pharmacological Management (First-Line)

These interventions should be implemented before considering pharmacological therapy:

Fluid and Salt Management

• Increase fluid intake to 2-3 liters daily unless contraindicated by heart failure or renal disease. 1
• Increase salt consumption to 6-9g daily if not contraindicated, as this helps maintain central volume. 1
• Note the paradoxical effect: Salt water actually attenuates the acute pressor response compared to plain water alone, so for immediate BP elevation, plain water (≥480 mL) is more effective, with peak effect at 30 minutes. 1, 5

Physical Maneuvers and Positioning

• Teach physical counter-pressure maneuvers including leg crossing, squatting, stooping, and muscle tensing during symptomatic episodes—these are particularly effective in patients under 60 years with prodromal symptoms. 1
• Elevate the head of the bed by 10 degrees during sleep to prevent nocturnal polyuria, maintain favorable fluid distribution, and ameliorate nocturnal hypertension. 1
• Advise gradual staged movements with postural changes to minimize orthostatic symptoms. 1

Compression Garments

• Use waist-high compression stockings (30-40 mmHg) and abdominal binders to reduce venous pooling. 1

Dietary Modifications

• Recommend smaller, more frequent meals to reduce post-prandial hypotension. 1
• Encourage physical activity and exercise to avoid deconditioning, which worsens orthostatic intolerance. 1

Pharmacological Management (When Non-Pharmacological Measures Fail)

The therapeutic goal is minimizing postural symptoms and improving functional capacity, not restoring normotension. 1

First-Line Pharmacological Options

Midodrine is the preferred first-line agent with the strongest evidence base among pressor agents:

• Initiate at 2.5-5 mg three times daily, with the last dose at least 3-4 hours before bedtime (avoid dosing after 6 PM) to prevent supine hypertension. 1, 6
• Mechanism: Alpha-1 adrenergic agonist causing arteriolar and venous constriction, increasing standing systolic BP by 15-30 mmHg for 2-3 hours. 1
• FDA-approved specifically for symptomatic orthostatic hypotension. 6
• Monitoring: Watch for supine hypertension (BP >200 mmHg systolic), bradycardia, urinary retention, and use cautiously in diabetics. 6

Fludrocortisone is an alternative or adjunctive first-line option:

• Initiate at 0.05-0.1 mg once daily, with individual titration to 0.1-0.3 mg daily (maximum 1.0 mg daily). 1
• Mechanism: Mineralocorticoid that increases plasma volume through sodium retention and vessel wall effects. 1
• Contraindications: Active heart failure, significant cardiac dysfunction, severe renal disease, or pre-existing supine hypertension. 1
• Monitoring: Check for supine hypertension (most important limiting factor), hypokalemia, peripheral edema, and congestive heart failure. 1

Droxidopa is particularly effective for neurogenic orthostatic hypotension:

• FDA-approved and especially beneficial in Parkinson's disease, pure autonomic failure, and multiple system atrophy. 1
• May reduce falls in these populations. 1

Combination Therapy

• For non-responders to monotherapy, consider combining midodrine with fludrocortisone. 1

Refractory Cases

Pyridostigmine may be beneficial for refractory orthostatic hypotension:

• Particularly useful in elderly patients who have not responded to other treatments. 1
• Has a favorable side effect profile compared to alternatives like fludrocortisone. 1
• Common side effects include nausea, vomiting, abdominal cramping, sweating, and salivation. 1

Special Considerations

Heart Failure with Low Blood Pressure

For patients with heart failure and reduced ejection fraction (HFrEF) presenting with low BP, guideline-directed medical therapy (GDMT) should be continued or optimized rather than discontinued, as treatment weakens the association between low BP and worse prognosis. 2

• The relative benefit of HF therapies remains consistent across baseline BP categories. 2
• Focus on addressing volume overload through gentle probing of target weight, increasing treatment time/frequency, and decreasing interdialytic weight gain in dialysis patients. 2

Dialysis Patients

For chronic hypotension in hemodialysis patients, increase dialysis time rather than reducing ultrafiltration goals, as these patients may tolerate peritoneal dialysis better than hemodialysis. 2

Medication Adjustments in Hypertensive Patients with Orthostatic Hypotension

• Switch (don't just reduce) BP-lowering medications that worsen orthostatic hypotension to alternative therapy. 1
• Prefer long-acting dihydropyridine calcium channel blockers or RAS inhibitors as first-line therapy for patients with both hypertension and orthostatic hypotension. 1
• Avoid RAS blockers in patients with established orthostatic hypotension due to vasodilatory effects. 1

Critical Monitoring Requirements

• Measure BP supine and standing at each visit to document orthostatic changes and detect supine hypertension. 1
• Monitor for supine hypertension development, which can cause end-organ damage—this is the most important limiting factor with pressor agents. 1
• Check electrolytes periodically when using fludrocortisone due to mineralocorticoid effects causing potassium wasting. 1
• Reassess within 1-2 weeks after medication changes. 1

Common Pitfalls to Avoid

• Do not assume salt supplementation enhances the acute pressor response—paradoxically, salt water attenuates the gastropressor response compared to plain water. 5
• Do not discontinue GDMT in heart failure patients solely due to low BP numbers without evidence of inadequate organ perfusion. 2
• Do not take midodrine if planning to be supine for any length of time, as this increases supine hypertension risk. 6
• Do not use fludrocortisone in patients with active heart failure or significant cardiac dysfunction. 1