From the Guidelines
Hypertension can be broadly classified into primary (essential) hypertension and secondary hypertension, with the latter being further subdivided into specific types such as renal parenchymal disease, renovascular hypertension, primary aldosteronism, chronic sleep apnea, and substance/drug-induced hypertension, as identified in the 2020 international society of hypertension global hypertension practice guidelines 1. The most common types of secondary hypertension in adults include:
- Renal parenchymal disease
- Renovascular hypertension
- Primary aldosteronism
- Chronic sleep apnea
- Substance/drug-induced hypertension These types of secondary hypertension can be identified in 5%–10% of hypertensive patients, and early diagnosis and targeted treatment have the potential to cure hypertension in some patients or improve blood pressure control and reduce the number of prescribed antihypertensive medications in others, as noted in the 2020 guidelines 1. Primary hypertension, on the other hand, is the most common type, accounting for about 90-95% of cases, and develops gradually without an identifiable cause, likely resulting from genetic factors, lifestyle choices, and environmental influences. Other types of hypertension, such as resistant hypertension, white coat hypertension, masked hypertension, malignant hypertension, isolated systolic hypertension, and gestational hypertension, also exist, each with distinct characteristics and management approaches, but the classification into primary and secondary hypertension, with its subtypes, provides a foundational understanding of the condition, as supported by the 2020 international society of hypertension global hypertension practice guidelines 1.
From the Research
Types of Hypertension
There are two main types of hypertension:
- Essential (primary) hypertension: this type of hypertension accounts for at least 95% of all cases of hypertension and has no identifiable cause 2, 3
- Secondary hypertension: this type of hypertension has a known cause and pathophysiologic process, and accounts for around 5-10% of all cases of hypertension 2, 4, 5
Causes of Secondary Hypertension
Some common causes of secondary hypertension include:
- Renal parenchymal disease 2, 4, 5
- Renovascular diseases 2, 4, 6, 5
- Coarctation of the aorta 2, 4, 5
- Cushing's syndrome 2, 4, 5
- Primary hyperaldosteronism 2, 4, 6, 5
- Pheochromocytoma 2, 4, 5
- Hyperthyroidism 2, 4
- Hyperparathyroidism 2, 5
- Obstructive sleep apnea 4, 6, 5
- Certain medications 6, 5
Diagnosis of Secondary Hypertension
Secondary hypertension should be suspected in patients with:
- Onset of hypertension before the age of 20 or after the age of 50 years 2
- Markedly elevated blood pressure or hypertension with severe end-organ damage 2
- Specific body habitus and ancillary physical findings 2
- Resistant or refractory hypertension 2, 5
- Specific biochemical tests that suggest the existence of certain disorders 2
- Abdominal diastolic bruits, decreased femoral pulses, or bitemporal hemianopias 2