Secondary Hypertension
Definition
Secondary hypertension refers to elevated blood pressure (hypertension) due to an identifiable underlying cause.
Aetiology
Most common causes: [Ref]
- Renal parenchymal diseases (e.g. diabetic nephropathy, hypertensive nephropathy, glomerulonephritis, polycystic kidney disease)
- Renovascular disease (e.g. atherosclerosis, fibromuscular dysplasia)
- Primary aldosteronism (Conn’s syndrome)
- Obstructive sleep apnoea
Less common causes: [Ref]
- Coarctation of the aorta
- Cushing’s syndrome
- Phaeochromocytoma
- Hyperthyoiridsm
The most common overall cause is renal parenchymal causes. [Ref]
The most common cause in young adults (18-40 y/o) is primary aldosteronism (Conn’s syndrome). [Ref]
When to Suspect
Secondary hypertension should be suspected in ANY of the following: [Ref]
- Resistant hypertension (uncontrolled BP despite 3 antihypertensive agents)
- Hypertension in <30 y/o
- Abrupt onset or worsening of hypertension
- Specific clinical features suggest an underlying disorder (e.g. hypokalaemia, evidence of renal disease)