Essential Hypertension is also known as Primary Hypertension or Idiopathic Hypertension. It is the most common type of hypertension affecting 85-90% of those with hypertension. Its physiological cause remains unidentified. It is generally asymptomatic. A doctor may perform an ECG and ECHO, but blood tests aren’t generally done. Allopathic/Conventional/Western medicine has no identifiable cause and a solution to it, though drugs generally target RAAS. 

The Renin Angiotensin Aldosterone System (RAAS)

Renin is a proteolytic enzyme(protease) synthesised by Kidneys.

Angiotensinogen is an inactive peptide synthesised by the Liver. 

Aldosterone is a steroid hormone made by the Adrenal Glands. 

JG cells in Kidneys produce Renin when:

• There is low Sodium in the blood.
• There is low blood flow or less water in the blood.
• Sympathetic Nervous System(SNS) stimulation by the Beta 1 receptors

Baroreceptors in Nephrons in the JG cells in afferent arterioles detect low blood volume thereby low water.

Chemoreceptors in Nephrons in the Macula Densa of the Distal Convoluted Tubule detect low Sodium thereby low salt.

The Left Common Carotid Artery has baroreceptors in the carotid sinus, they detect low blood pressure as they detect low blood flow. This also happens in the Aorta in the Aortic Sinus. It is done by the Vagus Nerve(more on this later).

The liver makes Angiotensinogen and Renin converts it to Angiotensin 1, as it breaks the bond between Leucine and Valine. 

Angiotensin 1 is a decapeptide and is inactive. It circulates in the blood and goes to the lungs. 

Angiotensin Converting Enzyme1 (ACE1) present in the lungs, converts Angiotensin 1 to Angiotensin 2.

ACE1 is prohypertensive and is a potent vasoconstrictor in itself. It further promotes fibrosis and inflammation. 

ACE2 is counter-regulatory to ACE1. It is antihypertensive and a vasodilator. It is antifibrotic and antiinflammatory in nature. It does so as it breaks down Angiotensin 2. 

Features of Angiotensin 2

• It is an octapeptide.
• Angiotensin 2 receptors are present in the vascular smooth muscles, in the endothelial layer. It is found in arteries, veins, arterioles and lymphatic systems.
• Angiotensin 2 is a potent vasoconstrictive agent. It does so by contracting the vascular smooth muscles. This increases the blood pressure.
• Angiotensin 2 increases thirst as it acts on the Hypothalamus and when water is consumed, it increases the blood volume.
• Angiotensin 2 acts on the posterior Pituitary Gland prompting it to release Anti-Diuretic Hormone(ADH). ADH goes to the Kidneys and increases water reabsorption, causing a rise in Blood Pressure.
• Angiotensin 2 stimulates Aldosterone release from Adrenal Glands, causing retention of Sodium and excretion of Potassium. 
• Angiotensin 2 constricts the blood vessel, causing water and sodium retention hence higher blood volume, together this leads to a significant rise in Blood Pressure. 
• Angiotensin 2 increases Calcium ions influx in the heart voltage channel hence greater force of contraction and high heart rate. This happens because of the higher Sodium retention, the Sodium channels in the heart can easily cause some influx or leakage of Sodium into the heart. This opens T-type Calcium channels in the heart and it in turn opens L-type Calcium channels.
• Angiotensin 2 stimulates the SNS, getting it in a loop.
• Angiotensin 2 can cause fat cells to grow from scratch and it can also cause fibrosis of fat cells making it inflamed. 
• Angiotensin 2 acts on the – Heart, Blood Vessels, Kidneys, Adrenal Glands, Brain and Nervous System.

Conventional Medicine treats it with drugs like 

• Angiotensin Converting Enzyme Inhibitor – pril
• Angiotensin 2 Receptor Blocker – sartan
• Diuretics 
• Calcium Channel Blockers – dipine
• Beta Blockers – olol 
• Alpha Blockers – zosin

This is a limited view that Conventional Medicine takes for something that affects us throughout the body. Let’s look at the bigger picture.

The Bigger Picture – Nutrition, Stress, Insulin, Cortisol and Sleep

The Sympathetic Nervous System(SNS) through the Sympathomedullary(SAM) Pathway stimulates the release of Epinephrine(Adrenaline) – 80% and Norepinephrine(Noradrenaline) – 20%, in the Adrenal Medulla of Adrenal Glands. The SNS nerves act directly on the SA Node and the AV Node, thus increasing the Heart Rate and Blood Pressure. Also, the SNS nerves in the Thoracolumbar region go to the blood vessels, particularly the Tunica Media, the muscular layer of the blood vessels that is responsible for dilation and constriction, resulting in vasoconstriction, thus increasing the Blood Pressure.

Epinephrine has a greater effect on the Heart and Norepinephrine has a greater effect on the Blood Vessels. Chemically, Epinephrine and Norepinephrine are very similar. Both Epinephrine and Norepinephrine work on Alpha and Beta receptors. However, Epinephrine has a greater effect on Beta receptors compared with Norepinephrine.

Alpha receptors are only found in the arteries. Beta receptors are in the heart, lungs, and arteries of skeletal muscles

Both Epinephrine and Norepinephrine can affect your heart, blood sugar levels, and blood vessels. However, Norepinephrine can also make your blood vessels become narrower, increasing blood pressure.

At the same time, though slower than the SAM Pathway, after a  10 minute lag, the Hypothalamus Pituitary Adrenal(HPA) Axis signals the Adrenal Cortex of the Adrenal Glands to release Cortisol. The effects of the HPA axis are significant and long lasting. 

Aldosterone, a mineralocorticoid and Cortisol, a glucocorticoid are made simultaneously in the body by the Adrenal Cortex of the Adrenal Glands. Aldosterone controls water and salt balance by reabsorbing Sodium and excreting Potassium.  Also Insulin increases Aldosterone activity.

Sodium follows Water and Water follows Sodium. So water retention means sodium retention. The main culprit for water retention is the sugar in our diet. How? Kidneys have insulin receptors. 

Whenever there is a low salt intake, the Kidneys hold on to the Sodium by signalling to raise insulin levels as a protective mechanism to preserve Sodium. Insulin directly stimulates Sodium reabsorption in the Distal Convoluted Tubules, hence retaining water. This goes to show that sugar retains water, not salt. Sodium and Salt retention increase the End Diastolic Volume which increases the Cardiac Output hence raising the Diastolic Pressure. Sodium, Calcium and SNS are involved in the depolarisation of the heart i.e. the contraction of the heart, increasing the heart rate. Further, inadequate Potassium intake or low amount of Potassium circulating in the blood also retains Sodium. Sodium functions inside the cells and Potassium does outside of it.

Vagus Nerve is the longest running cranial nerve of the Autonomic Nervous System and holds as much as 75% of the Parasympathetic Nervous System(PNS) fibres. It is a PNS nerve that runs from the brain to the large intestine connecting all the major internal organs through the heart, lungs and the digestive tract. The Vagus Nerve is made from the visceral fibres. 20% are efferent fibres, which provide Brain to Body communication. 80% are afferent fibres, which provide Body to Brain communication. Hypothalamus is the centre of SNS and PNS. Acetylcholine is the major neurotransmitter of the PNS. 

PNS repolarises the heart i.e. the relaxation of the heart. The right vagus innervates the SA Node and the left vagus innervates the AV Node. Potassium is also involved in the repolarisation of the heart.

The Vagal response is a Neuro-Cardiogenic-Gastrointestinal. The Vagal response is dependent on 2 factors

• Gut Issues
• Stress and Fear

If any of these issues are there, the Vagus Nerve doesn’t respond and Low Blood Pressure doesn’t stimulate the Vagus Nerve getting the body in a negative loop by activating SNS. Another connection between the gut and hypertension comes from Bile Salts. Bile Salts are important for the absorption of dietary fat. The lesser-known function of bile salts is that it protects against hypertension.

Fatty Liver inarguably plays a huge role in developing hypertension as Angiotensinogen is synthesized in the Liver by the visceral fat cells.  

Some nutritional deficiencies and imbalance also cause hypertension. The deficiencies in Vitamins and an imbalance (too much or too little) of minerals contribute to it. They are : 

• Vitamin B-Complex
• Vitamin C 
• Vitamin D
• Vitamin K2
• Calcium 
• Sodium
• Potassium
• Magnesium
• Phosphorous 

It’s the stimulation of SNS that starts a cascade that eventually leads to Essential Hypertension.  SNS is stimulated by

• Stress(Cortisol) 
• Poor Dietary Habits
• Low Salt Intake
• Poor Sleep

Once the SNS is activated it not only stimulates the release of Renin from the Kidneys but also increases Catecholamines. Catecholamines increase sugar production from the Liver through the process of Gluconeogenesis and Glycogenolysis and from the Pancreas through Glucagon, which in turn signals the release of Insulin. The body as a counter-regulatory mechanism releases Cortisol. Insulin and Cortisol are always involved in a loop, lowering one will help to lower the other. In simple words, Cortisol pushes up the blood sugar and Insulin tries to bring it down. Insulin Resistance is a vast topic in itself which I won’t discuss here, since we talked about Sodium, Potassium and Calcium, another important mineral is Magnesium as it activates the insulin receptors. 

Amylin (also called islet amyloid polypeptide, or IAPP) is a 37–amino acid peptide hormone co-secreted with insulin from pancreatic β-cells in response to food intake. Amylin influences the renin-angiotensin-aldosterone system (RAAS) as it stimulates the plasma renin and aldosterone concentration. Amylin also regulates the Sympathetic Tone (SNS) directly from the brain.  

Sugar is the biggest stimulator of Insulin.

Stress is the biggest stimulator of Epinephrine and Cortisol.

Poor Sleep (Quality and Duration) is the biggest disrupter of normal Cortisol and Insulin functioning as it keeps those constantly elevated. 

Essential Hypertension is not because of Salt, it is because of Sugar, Stress, Sleep issues and Nutritional Deficiencies.

Let me tell you a secret, come closer – There is an involvement of immune dysregulation that acts as a major contributor towards the pathogenesis of Hypertension.

Tests 

Here is a list of tests that every person with Essential Hypertension must undergo.

• Insulin Fasting
• Insulin Postprandial
• Fasting Blood Sugar
• Postprandial Blood Sugar
• C-Peptide
• Renin – Direct
• Aldosterone
• Cortisol (Morning)
• Cortisol (Evening)
• CBC
• Lipid Profile
• Kidney Function
• Lactate 
• Electrolytes- Sodium, Potassium, Calcium, Phosphorus, Chloride, Magnesium, Bicarbonate
• Liver Function
• Thyroid Profile
• HbA1C
• Vitamin B9
• Vitamin B12
• Vitamin D
• ESR
• hs- CPR
• ECG
• ECHO
• Ultrasound Whole Abdomen and Pelvis 
• Asymmetrical Dimethylarginine (ADMA) – tests for Endothelial Dysfunction