From the Guidelines
The initial laboratory workup for elevated blood pressure should include a complete blood count, urinalysis, serum electrolytes, blood urea nitrogen, serum creatinine, glucose, fasting lipid profile, liver function tests, iron studies, and thyroid-stimulating hormone levels, as well as a 12-lead electrocardiogram, as recommended by the most recent guidelines 1.
Initial Laboratory Tests
The following tests are essential for the initial evaluation of patients with elevated blood pressure:
- Complete blood count to identify anemia or infection
- Urinalysis to detect protein or blood in urine, suggesting kidney damage
- Serum electrolytes, including calcium and magnesium, to evaluate electrolyte balance
- Blood urea nitrogen and serum creatinine to assess kidney function
- Glucose and fasting lipid profile to evaluate cardiovascular risk factors
- Liver function tests to assess liver health
- Iron studies, including serum iron, ferritin, and transferrin saturation, to evaluate iron deficiency or overload
- Thyroid-stimulating hormone levels to rule out thyroid disorders
- 12-lead electrocardiogram to evaluate heart rhythm and structure
Rationale
These tests are crucial for identifying underlying causes of hypertension, assessing organ damage, evaluating cardiovascular risk, and guiding treatment decisions, as emphasized by the 2022 AHA/ACC/HFSA guideline for the management of heart failure 1. Early detection of abnormalities can prevent complications like heart disease, stroke, and kidney failure.
Additional Considerations
Additional tests, such as thyroid function tests and plasma aldosterone and renin activity, may be considered if secondary hypertension is suspected, as noted in previous guidelines 1. However, the most recent and highest-quality study 1 provides the most up-to-date recommendations for initial laboratory tests in patients with elevated blood pressure.
From the Research
Initial Laboratory Tests for Hypertension
The initial laboratory tests for hypertension are crucial in determining the cause and extent of the condition. According to 2, a focused history and physical examination, and a handful of basic tests are enough for most patients.
- Basic tests may include:
- Serum chemistry
- Electrocardiogram (ECG)
- Chest radiograph
- Urinalysis
- Funduscopy
- Biochemical investigations, as mentioned in 3, serve to identify those hypertensive individuals who are at higher risk on the basis of evidence of dysglycaemia, dyslipidaemia, renal impairment, or target organ damage and to exclude identifiable causes of hypertension.
Specific Tests for Hypertension
In patients with severely elevated blood pressure, the following tests may be ordered:
- Serum chemistry (obtained in 73% of patients) 4
- ECG (performed in 53% of patients) 4
- Chest radiograph (performed in 46% of patients) 4
- Urinalysis (performed in 43% of patients) 4
- Funduscopy (documented in 36% of patients) 4
Pediatric Patients with Hypertension
For pediatric patients with hypertension, the evaluation should include: