Causes of Hypertension

Causes of secondary hypertension

Renal parenchymal disease (most common cause)^1,2

Typical signs/symptoms

• Bilateral upper abdominal masses at physical examination

Diagnosis

• Abdominal ultrasound
• Urine test for proteins, leucocytes, erythrocytes
• Blood test for elevated serum creatinine

Renovascular hypertension (caused by renal artery stenosis)^1,2

Typical signs/symptoms

• Abdominal bruit with lateralization (~40% of patients)
• Hypokalaemia
• Polyglobulia
• Progressive decline in renal function

Diagnosis

• Difference >1.5 cm in length between kidneys (~60% of patients)
• Colour Doppler sonography/gadolinium-enhanced magnetic resonance angiography to detect renal artery stenosis
• Confirmed with intra-arterial subtraction angiography

Primary aldosteronism (Conn’s syndrome) (less than 1% of all causes of hypertension)^1,2

Typical signs/symptoms

• Muscle weakness
• Frequent/night-time urination
• Headache
• Excessive thirst
• Pins and needles sensation
• Visual disturbances
• Temporary paralysis
• Muscle twitching and cramps
• Hypokalaemia
• (Mild) hypernatraemia
• Hyperkaluria (high urine potassium)

Diagnosis

• Positive screening for hypokalaemia
• Confirmed by low plasma renin activity (<1 ng/mL/h) and elevated plasma aldosterone levels (ratio aldosterone: renin >50)
• Positive rating on fludrocortisone suppression test can confirm further

Cushing’s syndrome (~80% of people with this condition have hypertension)^1,2

Typical signs/symptoms

• Weight gain
• Buffalo hump, supraclavicular fat pad, moon-face
• Purple abdominal striae
• Hirsutism (female)
• Impotence (male)
• Osteoporosis
• Myopathy

Diagnosis

• 24-hour urinary cortisol values >110 mmol/L (40 µg)
• Confirmed by urinary cortisol excretion level >27 mmol/L (10 µg)/day or >140 mmol/L (5 µg/dL) in a 2-day or overnight low-dose dexamethasone suppression test (0.5 mg every 6 hours for eight doses)

Coarctation of the aorta (rare form of hypertension usually in children and young adults)^1,2

Typical signs/symptoms

• Mid-systolic murmur over the anterior part of the chest and back
• Delayed and decreased femoral pulse relative to the radial pulse

Diagnosis

• Physical examination
• Confirmed by echocardiogram or electrocardiogram
• Also possible to confirm by magnetic resonance imaging or computerized tomography scan

Drug-induced hypertension^1,2

Typical signs/symptoms

• Elevated blood pressure related to intake of:
  • Liquorice
  • Oral contraceptives
  • Steroids
  • Non-steroidal anti-inflammatory drugs
  • Cocaine/amphetamines
  • Erythropoietin
  • Cyclosporins

Diagnosis

• Blood pressure measurements repeated over a period of time

Phaeochromocytoma (very rare cause of secondary hypertension)^1,2

Typical signs/symptoms

• Severe headache
• Palpitations
• Rapid heart rate
• Sweating
• Flushing
• Chest pain
• Abdominal pain
• Nervousness
• Irritability
• Increased appetite
• Loss of weight
• High blood pressure
• Sleeping difficulty
• Hand tremor

Diagnosis

• Biochemical detection of catecholamines (noradrenaline and adrenaline) and metadrenalines in 24-hour urine tests

References