Secondary Hypertension

Cardiology (12%) Core Clinical Conditions

1B: Able to identify the condition as a possible diagnosis: may not have the knowledge or resources to confirm the diagnosis or to manage the condition safely, but can take measures to avoid immediate deterioration and refer appropriately.

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Definition Aetiology Pathophysiology Risk factor Sign and Symptoms Investigations Diagnosis Management

Secondary hypertension is a form of hypertension that, by definition, has a known underlying primary cause. Tumors, renal problems, and endocrine disorders are only a few of the various causes.

• Diabetes: causes damage to the kidney's filtering system, leading to HTN.

• Polycystic kidney disease: cyst in the kidneys impede with normal kidney function causing HTN 

• Cushing syndrome 

• Pheochromocytoma: adrenal gland tumor causes overproduction of adrenaline and noradrenaline, causing increased blood pressure. 

• Thyroid disorders 

• Hyperparathyroidism: overproduction of parathyroid hormone causes a rise of calcium, causing increased blood pressure.  

• Aortic coarctation: is a narrowing of the aorta that causes high blood pressure. 

• Sleep apnea  

• Obesity 

• Pregnancy 

• Medications

• Aldosteronism : overproduction of aldosterone causes salt and water retention, raising your blood pressure.

The main causes of hypertension are increased cardiac output and high vascular resistance. 

As mentioned above, there are several known causes for secondary hypertension. 

Having a medical condition that might raise blood pressure, such as kidney, artery, heart, or endocrine system issues, is the biggest risk factor for secondary hypertension.

Even when blood pressure has risen to dangerously high levels, secondary hypertension frequently exhibits no distinct symptoms, similar to primary hypertension.

• Headache

• Chest pain

• Shortness of breath 

• Dizziness

• Visual disturbance

• Urine test- check for hematuria 

• Urine albumin:creatinine ratio (check for protein the urine)

• Bloods: Hba1c, U&E, cholesterol 

• Fundoscopy (any presence of hypertensive retinopathy) 

• 12 lead ECG (check cardiac function)

• Q-risk assessment (if more than 10% or more consider starting on a statin)

If clinic blood pressure is between 140/90 mmHg - 180/120 mmHg you arrange a 24 hr ambulatory blood pressure (ABPM) or a home readings to confirm HTN. 

There are different stages of HTN: 

Stage 1 Hypertension

Home BP >140/90 ; ABPM>135/85

Stage 2 Hypertension

Home BP >160/100 ; ABPM>150/95

Stage 3 Hypertension

Home BP >180/120

Be aware of the following medications: 

• ACE inhibitors (ACEi) e.g Ramipril 

• Angiotensin receptor blockers (ARBs) e.g. Losartan

• Calcium-channel blockers (CCB) e.g Amlodipine

• Diuretics e.g. Indapamide 

• Alpha-blockers e.g. Doxazosin

• Beta-blockers e.g. Bisoprolol 

Stepped approach:

Step 1

• ACEi or ARB - if not diabetic and under 55 years old and not of black African or African-Caribbean ancestry.

Note: Offer an ARB to treat hypertension if an ACE inhibitor is not tolerated, perhaps due to cough.

• CCB - if above 55 years old and do not have type 2 diabetes and are also of black African or African-Caribbean ancestry.

Note:Offer a thiazide-like diuretic to treat hypertension if a CCB is not tolerated, perhaps due to oedema. Indapamide should be started instead of other thiazide diuretics. 

Step 2 

If HTN is not well controlled with an ACEi/ARB, offer the following in addition to step 1: 

• CCB or thiazide-like diuretic

If HTN is not well controlled with a CCB, offer the following in addition to step 1: 

• ACEi or ARB or a thiazide-like diuretic

Step 3 

If HTN is not well controlled with step 2, then offer the following: 

• ACEi or ARB + CCB + thiazide-like diuretic

Step 4 

If HTN is not well controlled with step 3, you can regard them as treatment resistant hypertension. Therefore, you might want to consider:

• Discussing adherence 

• Adding a fourth antihypertensive. For example, a low-dose spironolactone for patients who have a blood potassium level of 4.5 mmol/l or less. Or you can consider an alpha blocker such as doxazosin if the patient’s blood potassium level is above 4.5 mmol/l 

• Seek specialist advice

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