What is the laboratory evaluation for hypertension?

From the Guidelines

Laboratory evaluation for elevated blood pressure should include serum creatinine, eGFR, urine ACR, a comprehensive metabolic panel (CMP), complete blood count (CBC), urinalysis, lipid profile, and electrocardiogram (ECG) as recommended by the most recent guidelines 1. The CMP assesses kidney function through blood urea nitrogen (BUN) and creatinine levels, while also measuring electrolytes like sodium and potassium which can influence blood pressure.

• A CBC helps identify anemia or infections that might contribute to hypertension.
• Urinalysis can detect protein or blood in urine, suggesting kidney damage from long-standing hypertension.
• A lipid profile measures cholesterol levels, important because hyperlipidemia often coexists with hypertension as cardiovascular risk factors.
• Thyroid function tests may be ordered since thyroid disorders can cause secondary hypertension.
• In some cases, additional specialized tests might be necessary, such as plasma aldosterone and renin activity to evaluate for primary aldosteronism, or 24-hour urine collection for metanephrines to rule out pheochromocytoma. These tests help determine if hypertension is primary (essential) or secondary to another condition, guide treatment decisions, and establish baseline values to monitor for end-organ damage over time, as supported by the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1. The 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults also recommends laboratory measurements to facilitate CVD risk factor profiling, establish a baseline for medication use, and screen for secondary causes of hypertension 1.

From the Research

Lab Evaluation for Elevated Blood Pressure

• The evaluation of patients with elevated blood pressure should include accurate blood pressure measurement, a focused history and physical examination, and basic tests to determine if the hypertension is primary or secondary, and to identify other cardiovascular risk factors and target organ damage 2.
• Biochemical investigations, such as routine and specialized tests, are essential for evaluating patients with hypertension to identify those at higher risk and to exclude identifiable causes of hypertension 3.
• The main target of biochemical testing is to identify patients with a specific and treatable etiology of hypertension, and to risk stratify patients and tailor their management and treatment 3.
• Patients with severely elevated blood pressure should be evaluated for acute target organ damage, and their medical regimen should be adjusted, and they should be instructed to follow up promptly for reassessment 4.
• Tests that may be ordered for patients with severely elevated blood pressure include serum chemistry, ECG, chest radiograph, urinalysis, and funduscopy, although not all patients require all of these tests 4.
• Patients with mild to moderate hypertension may only require a simple schedule of investigations, including measurements of body mass index, random cholesterol, routine blood chemistry, and urinalysis 5.
• More detailed investigations can be reserved for special groups, such as those with peripheral vascular disease or abnormal renal function, or those with severe hypertension or resistance to antihypertensive treatment 5.
• Abnormal basic metabolic panel findings, such as electrolyte imbalances or renal function abnormalities, can have important implications for nursing care and should be considered in the evaluation and management of patients with hypertension 6.