Table 5 Common causes of secondary hypertension, symptoms that raise clinical suspicion and recommended investigations.
Condition | Clinical Suspicion | Investigations |
|---|---|---|
Kidney disease | Usually asymptomatic with only incidental finding of elevated serum creatinine or abnormalities in the urinary sediment. People with diffuse atherosclerotic disease can show a drop in eGFR after treatment with ACE-I/ARB. History of recurrent UTIs and family history of kidney disease should be evaluated. | Serum creatinine, urine dipstick, urine sample for albumin:creatinine ratio and protein:creatinine ratio. Consider renal imaging (US, MRA, CT) based on laboratory findings and clinical situation. |
Primary hyperaldosteronism | Spontaneous/thiazide induced hypokalaemia, adrenal incidentaloma. Majority of cases are detected in asymptomatic individuals with normokalaemia. | Renin/aldosterone ± adrenal imaging (adrenal MRI/HRCT) followed by confirmatory tests and/or adrenal vein sampling. |
Obstructive Sleep Apnoea | Snoring, daytime sleepiness, elevated BMI or neck circumference and non-dipping profile on 24-h ABPM. | Validated questionnaires such as Epworth Sleepiness Scale or STOP-BANG score. Overnight oxygen saturation monitor. |
Pheochromocytoma and Paraganglioma | Paroxysmal or sustained hypertension, headaches, palpitations, hyperhidrosis, and non-CV symptoms such as weight loss or hypoglycaemia. | Plasma free or urinary fractionated metanephrines ± adrenal MRI/HRCT ± functional imaging and/or clonidine suppression test. |
Cushing syndrome | Truncal obesity, striae, glucose intolerance and repeated infections. | Overnight dexamethasone suppression test and 24-h urine free cortisol. ACTH is needed to confirm hypercortisolism and imaging is required to differentiate between adrenal and pituitary causes. |
Thyroid and parathyroid disorders | Usually asymptomatic: symptoms may include palpitations, tiredness, polyuria, muscle weakness, anxiety, tremor, irritability. | Evaluation of calcium, PTH, TSH and thyroid hormones. Thyroid and parathyroid ultrasound. |
Aortic coarctation | Usually asymptomatic: signs may include radio-femoral delay and lower blood pressure in the lower extremities. | Aorta MRA/CT. |
Further information on the secondary causes of hypertension can be found in the accompanying Supplementary File. | ||
