Hypertension

Fasting laboratory tests

• Serum electrolytes
• Serum creatinine with eGFR
• Fasting plasma glucose
• Lipid profile
• FBC (haemoglobin)if neededHaemoglobin or haematocrit: basic test in the ESH 2023 work-up ^[2]; ESC 2024 lists it among the tests that screen for a secondary cause (polycythaemia) ^[3]. It is not in the HAS initial tests ^[4].
• HbA1cif neededESH 2023 pairs fasting plasma glucose with HbA1c ^[2]; ESC 2024 measures HbA1c only if fasting plasma glucose is raised ^[3]; HAS does not list it ^[4]. Outside NABM indications in people without diabetes: write “NR” (not reimbursable in France) ^[5].
• Serum urateif neededRoutine test in the ESH 2023 work-up ^[2]; neither HAS ^[4] nor ESC 2024 ^[3] retains it in the initial tests.
• Serum calciumif neededRetained by ESH 2023 ^[2] and by ESC 2024, which uses it to screen for hyperparathyroidism ^[3]; absent from the HAS initial tests ^[4]. See the page “Hypercalcaemia”.
• TSHif neededESC 2024 lists it among the tests screening for thyroid dysfunction, a secondary cause of hypertension ^[3]; it is not in the HAS initial tests ^[4] nor in the ESH 2023 list ^[2].
• Plasma aldosterone and renin, with aldosterone/renin ratio (if hypokalaemia, hypertension ≥ 180/110 mmHg, adrenal incidentaloma, sleep apnoea syndrome or family history of early hypertension or stroke before age 40; sampling conditions: see the "Resistant hypertension" tab)if neededThe 2016 French consensus recommends this screening in severe hypertension (≥ 180/110 mmHg), resistant hypertension, hypertension with hypokalaemia or with an adrenal incidentaloma, and looking for a familial form in young people with a family history of hypertension, stroke or hyperaldosteronism ^[6]. The 2025 American recommendation adds obstructive sleep apnoea syndrome and proposes considering it from 140/90 mmHg ^[7]; ESC 2024 considers it in every patient with confirmed hypertension ^[3]. The earlier French consensus does not retain obstructive sleep apnoea syndrome ^[6]. In the United States, the first measurement is done on treatment (except mineralocorticoid receptor antagonists) ^[7]; in France, antihypertensives that distort the result are stopped first ^[8].

Urine tests

• Urine protein:creatinine ratio (spot sample)
• Haematuria (blood testing, urine dipstick)if neededESH 2023 asks for a multiparameter urine dipstick in all patients ^[2] and ESC 2024 for urine tests, with a dipstick for blood and protein when kidney damage is suspected ^[3]; HAS retains only the search for proteinuria, whatever the method ^[4]. To be requested in case of proteinuria or suspected nephropathy.
• Urine albumin:creatinine ratio (ACR)if neededESH 2023 and ESC 2024 recommend it in every patient with hypertension ^[2,3]; HAS considers it unnecessary, except in non-proteinuric patients with diabetes ^[4].

Laboratory tests

• Serum electrolytes
• Serum creatinine with eGFR

Urine tests

• Urine protein:creatinine ratio (spot sample)
• Haematuria (blood testing, urine dipstick)if neededESH 2023 makes the urine dipstick a routine test in every patient with hypertension ^[2]; the HAS follow-up laboratory check looks for proteinuria, whatever the method ^[4]. Useful in case of proteinuria or known nephropathy.

Fasting laboratory tests

• Serum electrolytes
• Serum creatinine with eGFR
• Fasting plasma glucose
• Lipid profile

Urine tests

• Urine protein:creatinine ratio (spot sample)
• Haematuria (blood testing, urine dipstick)if neededESH 2023 makes the urine dipstick a routine test in every patient with hypertension ^[2]; the HAS follow-up laboratory check looks for proteinuria, whatever the method ^[4]. Useful in case of proteinuria or known nephropathy.

Laboratory tests

• Plasma aldosterone/renin ratio
• Dexamethasone suppression test for cortisol measurement

24-hour urine collection

• Urinary metanephrines
• 24-hour urinary free cortisol

Fasting laboratory tests, in the morning

• Serum electrolytes
• Serum creatinine with eGFR
• Fasting plasma glucose
• Lipid profile
• FBC
• Serum calcium
• TSH
• Plasma aldosterone and renin, with aldosterone/renin ratio (sampling conditions: see the note)

Urine tests

• Urine protein:creatinine ratio (spot sample)
• Haematuria (blood testing)
• 24-hour urinary sodium (checks the normal-sodium diet at the time of the renin-aldosterone assay)

Depending on the clinical picture

• 24-hour urinary metanephrines (if episodes of headache, sweating, palpitations)if neededEpisodes of headache, sweating, palpitations: phaeochromocytoma is one of the main causes of secondary hypertension, and measurement of urinary metanephrines and normetanephrines is among the investigations of secondary hypertension ^[4].
• 24-hour urinary free cortisol or overnight dexamethasone suppression test (if signs of hypercortisolism)if neededSigns of hypercortisolism: Cushing's syndrome is one of the main causes of secondary hypertension; measure urinary free cortisol or plasma cortisol after a dexamethasone test ^[4]. See the page “Cushing's syndrome”.
• PTHif needednon-French guidelineHypercalcaemia in the tests: the serum calcium of the baseline tests is used to screen for hyperparathyroidism ^[3]; see the page “Hypercalcaemia”.
• Serum phosphateif needednon-French guidelineHypercalcaemia in the tests: the serum calcium of the baseline tests is used to screen for hyperparathyroidism ^[3]; see the page “Hypercalcaemia”.

• Acute organ damage (chest pain, dyspnoea, neurological deficit, confusion, seizures, visual disturbance, pregnancy): no tests in the community, refer to the emergency department.
• Without acute organ damage: no hospital admission; tests from the "Initial tests" tab without delay, and specialist opinion (search for secondary hypertension).

Laboratory tests

• Serum electrolytes (potassium)
• Serum creatinine (GFR by the 2009 Schwartz formula)
• ASTif neededOverweight or obese child (BMI > 95th percentile) or family history of dyslipidaemia ^[12].
• ALTif neededOverweight or obese child (BMI > 95th percentile) or family history of dyslipidaemia ^[12].
• Fasting lipid profile (same context)if neededOverweight or obese child (BMI > 95th percentile) or family history of dyslipidaemia ^[12].
• Fasting plasma glucose (same context)if neededOverweight or obese child (BMI > 95th percentile) or family history of dyslipidaemia ^[12].

Urine tests (first morning urine)

• Urine sediment with red cell count (haematuria)
• Urine protein:creatinine ratio (spot sample)