Different Types of Hypertension and What They Mean for Your Health

Adults should have systolic and diastolic blood pressure readings of less than 120 and 80 mmHg, respectively. It varies slightly based on your age and gender. High blood pressure, or hypertension, occurs when the pressure in your arteries exceeds these normal levels. Understanding the different types of hypertension is crucial because it enables treatment regimens to be tailored to the individual requirements of each patient. All of the types of hypertension demand careful handling because of their capacity to significantly impair a person's quality of life and overall well-being. 

Let us examine various types of hypertension, each with unique causes and characteristics.

Primary or Essential Hypertension

This type of high blood pressure is the most common and asymptomatic. It usually develops slowly over the years and doesn’t come from any specific health issue. Most people do not even notice any symptoms, and it is usually only found by routine blood pressure checks.

Causes: While the precise cause is unknown, several factors, such as ageing, genetics, being overweight, smoking, consuming a lot of salt, and going through a lot of stress, can be contributing factors. Other factors, including environment, lifestyle, and heredity, can lead to the narrowing of arteries and increased blood pressure.

Types of Primary Hypertension 

While not classified into distinct categories as some other medical conditions may be, several factors can be taken into consideration to classify: 

1. 1. Age-Related Hypertension: Blood pressure generally increases with age due to alterations in the elasticity of blood vessels and other physiological changes associated with ageing.
2. 2. Lifestyle-Related Hypertension: This category is influenced by various factors, including high sodium intake, obesity, a sedentary lifestyle, tobacco use, and excessive alcohol consumption.
3. Genetic Hypertension: Family history and genetic predispositions significantly contribute to the risk of developing hypertension. 
4. Gender Differences: Although both men and women are susceptible, the risk factors and patterns may vary by gender and age. 
5. Ethnic Variations: Certain ethnic groups exhibit a higher predisposition to hypertension. 

Secondary Hypertension

Elevated blood pressure from an underlying illness is known as secondary hypertension. In contrast to primary hypertension, which lacks a singular identifiable cause, secondary hypertension is frequently attributable to another health issue that disrupts the regulation of blood pressure. 

Causes: Several factors, including hormonal disorders like Cushing's syndrome, sleep apnoea, certain medications (including some birth control pills), birth defects, and renal problems like long-term kidney disease, can be associated with high blood pressure.

Types of Secondary Hypertension 

Below are several prevalent forms of secondary hypertension:

1. Renal hypertension: Renal diseases or conditions that affect kidney function, like renal artery stenosis, which is characterised by the narrowing of the arteries supplying blood to the kidneys, can cause this type of hypertension.
2. Endocrine Hypertension: Hormonal imbalances may result in increased blood pressure. Notable conditions include:

• Excess aldosterone produced by the adrenal glands is known as primary aldosteronism.
• Overproduction of cortisol by the adrenal glands is known as Cushing's syndrome.
• A rare adrenal tumour known as a phéochromocytoma causes an overabundance of noradrenaline and adrenaline.
• Blood pressure can be impacted by thyroid disorders, including both hyperthyroidism and hypothyroidism.

1. Cardiovascular Hypertension: This category includes issues that impact the heart and blood vessels, like coarctation of the aorta (when the aorta is narrowed from birth) and pulmonary hypertension, which affects the arteries in the lungs.
2. Medication-Induced Hypertension: Certain medications may elevate blood pressure as a side effect. This includes non-steroidal anti-inflammatory drugs (NSAIDs), specific antidepressants, and corticosteroids.
3. Obstructive Sleep Apnoea: This sleep disorder, characterised by recurrent interruptions in breathing during sleep, can contribute to elevated blood pressure due to repeated fluctuations in oxygen levels.
4. Pregnancy-Related Hypertension: Conditions such as preeclampsia and gestational hypertension may arise during pregnancy and can result in elevated blood pressure.
5. Hyperparathyroidism: The overactivity of the parathyroid glands, leading to an excess of calcium in the bloodstream, can also contribute to increased blood pressure.

Portal Hypertension

Portal hypertension occurs when there's high blood pressure in the veins from your liver and digestive organs. Liver function is usually unaffected in the early stages of the condition. As the body tries to deal with the blockage, it can cause the spleen to get bigger and lead to some alternative blood flow routes.

Types of Portal Hypertension and Their Causes

This condition can cause multiple complications and is classified into different types based on the underlying cause and the location of the increased pressure. Below is an overview of the different types of portal hypertension:

Prehepatic Portal Hypertension: This type occurs before blood enters the liver.

Causes:

• Portal Vein Thrombosis: A thrombus forming in the portal vein that obstructs blood flow.
• Congenital Anomalies: Birth defects causing obstructions to the portal vein or its branches.
• Splenic vein thrombosis: By obstructing blood flow into the portal vein, thrombosis in the splenic vein may also be a factor in prehepatic portal hypertension.

2. Intrahepatic Portal Hypertension This type arises within the liver due to increased resistance to blood flow in the intrahepatic vasculature. Characteristics related to certain indicators of liver disease, such as elevated liver enzyme levels and jaundice (yellowing of the skin),  ascites, or swollen abdomen, varicose veins in the oesophagus, and hepatic encephalopathy—basically, brain fog from liver failure—are some common problems associated with this.

   Causes:

• Cirrhosis: The most common cause where fibrosis and scarring from prolonged liver damage obstruct blood circulation.
• Hepatitis: Over time, cirrhosis can develop from chronic hepatitis.
• Liver Tumours: The liver can become clogged with benign and malignant tumours that block blood flow.
• Schistosomiasis: A parasitic infection that can cause portal hypertension and liver fibrosis.

3. Posthepatic portal hypertension: It develops due to the elevated resistance in the inferior vena cava or hepatic veins after blood leaves the liver. When there is venous congestion, swelling frequently occurs in the lower extremities and abdomen. In such cases, the liver typically remains unaffected, in contrast to situations where there is direct pressure on the liver itself.

Causes:

• Budd-Chiari Syndrome: Hepatic vein obstruction brought on by thrombosis or other medical disorders.
• Right heart failure: circumstances like congestive heart failure can cause the hepatic veins to become more pressured, which can result in portal hypertension.
• Tricuspid Valve Insufficiency: A heart's tricuspid valve may not close completely, leading to elevated venous pressure.

Diagnosis of Portal Hypertension:

• Imaging: To see the veins and find any blockages, methods like ultrasound, CT scan, or MRI can be used.
• Endoscopy: This technique is used to assess the severity of varicose veins.
• Liver biopsy: This procedure may be used to evaluate liver fibrosis or damage.

Management of Portal Hypertension:

• Medication: anticoagulants to treat thrombosis, beta-blockers to lower portal pressure, and diuretics for ascites.
• Procedures: endoscopic band ligation for varicose veins, transjugular intrahepatic portosystemic shunt (TIPS) to lower portal pressure, or liver transplantation in dire circumstances

Pulmonary Hypertension

Blood pressure is higher in the pulmonary arteries—which carry blood from the heart to the lungs—and is a sign of pulmonary hypertension (PH). The right side of the heart may be severely strained due to this elevated pressure, which may cause multiple symptoms such as dyspnoea, exhaustion, and discomfort in the chest. Pulmonary hypertension is categorised into several types based on its underlying causes:

1. Pulmonary arterial hypertension (PAH) is a rare and progressive form of pulmonary hypertension, characterised by elevated blood pressure resulting from the narrowing or obstruction of the small pulmonary arteries.
2. Pulmonary hypertension due to left heart disease is caused by issues with the left side of the heart, such as left ventricular dysfunction, often associated with heart failure, and diseases affecting the aortic or mitral valves, which can elevate pulmonary circulation pressure.
3.  Pulmonary Hypertension Lung issues and low oxygen are linked to long-term conditions that lower blood oxygen levels. Some common ones are chronic obstructive pulmonary disease (COPD), sleep apnoea (which causes low oxygen levels while you sleep), and interstitial lung disease (which involves inflammation and scarring of the lung tissue).
4. Chronic thromboembolic pulmonary hypertension (CTEPH) is attributable to persistent blood clots within the pulmonary arteries, which can result in long-term obstruction and elevated pressure.
5. Pulmonary hypertension from less common causes includes sarcoidosis, an inflammatory disease affecting the lungs and lymphatic system, and various vascular diseases that impact blood vessels outside the pulmonary circulation, such as certain vasculitis.

Conclusion

Each type of hypertension necessitates a tailored approach to diagnosis and management, often involving a combination of pharmacological treatments, lifestyle modifications, and, in some cases, surgical interventions, depending upon the underlying cause and severity of the condition.

Frequently Asked Questions

What are the four types of hypertension?

There are four types of hypertension: essential or primary hypertension, secondary hypertension, pulmonary hypertension, and portal hypertension. Among these, the most common type of hypertension is primary hypertension.

What are type 1 and type 2 hypertension?

Type 1 hypertension, or primary hypertension, is the most common type of high blood pressure. It’s not triggered by other health issues or medications. On the other hand, type 2 hypertension, also called secondary hypertension, happens because of an underlying health problem or as a side effect of some medications.

What are the 5 different levels of hypertension?

Hypertension is classified into five stages based on blood pressure readings: 

1. Normal: systolic < 120 mm Hg and diastolic < 80 mm Hg.
2. Pre-hypertension: systolic 120-139 mm Hg and diastolic 80-89 mm Hg.
3. Stage 1 hypertension: systolic 140-159 mm Hg and diastolic 90-99 mm Hg.
4. Stage 2 hypertension: systolic ≥ 160 mm Hg and diastolic ≥ 100 mm Hg.
5. Hypertensive Crisis: Systolic ≥ 180 mm Hg or diastolic ≥ 120 mm Hg.