What is essential hypertension?

Essential hypertension is high blood pressure that has no identifiable cause.

Most cases of high blood pressure are primary (essential) hypertension, which means that there’s no identifiable cause for the condition. This type of high blood pressure affects 70% of people with the condition.

Secondary hypertension is where there is a specific underlying cause for the high blood pressure, such as kidney disease or hormonal problems. Secondary hypertension accounts for about 30% of cases.

How does essential hypertension develop?

The kidneys are responsible for controlling your body’s water and salt levels. They do this by controlling how much sodium and water you take in and eliminate from your body through your urine. If your kidneys don’t work properly, they can’t regulate sodium levels effectively – which can lead to an increase in fluid retention and therefore an increase in blood volume (and therefore your blood pressure).

Essential hypertension is often associated with other conditions such as obesity and diabetes mellitus (type 2 diabetes). These conditions can affect how well your kidneys work by increasing the workload on them or causing damage to their cells through excess sugar (glucose) in the bloodstream.

Secondary hypertension

Secondary hypertension is not due to any obvious cause. It is a condition that develops from other conditions and causes high blood pressure. Secondary hypertension can be caused by kidney disease, heart failure, hormonal problems and some medications. The most common types of secondary hypertension are:

Renovascular Hypertension – Renal artery stenosis or narrowing of the artery that supplies blood to the kidneys can lead to high blood pressure in the upper extremities as well as increasing your risk for heart attack or stroke.

Medication-Induced Hypertension – Some medications increase blood pressure, such as birth control pills containing estrogen, beta blockers and diuretics.

Pregnancy-Induced Hypertension – Pregnancy causes increased fluid retention which can result in high blood pressure. If your blood pressure continues to rise after delivery, it may be due to preeclampsia (pregnancy-induced hypertension with severe proteinuria).

Cushing’s Syndrome – Cushing’s syndrome is caused by prolonged exposure to high levels of cortisol (a hormone produced by the adrenal gland). This condition often causes obesity and high blood pressure (hypertension), especially if left untreated for an extended period of time.

Symptoms of essential hypertension

The symptoms of essential hypertension can vary from person to person. They may include:

• Headaches
• Nausea and vomiting
• Dizziness or lightheadedness
• Fatigue or lack of energy
• Palpitation (feeling heart beats)
• Chest pain or discomfort
• Swelling in the legs, ankles and feet

Causes of essential hypertension

The cause of essential hypertension is unknown. Some research has shown that this condition can be inherited from parents, but other studies have not confirmed this finding.

The following are some possible causes of essential hypertension:

Obesity and high blood pressure (hypertension). Overweight children and adolescents are more likely to develop high blood pressure than their normal-weight peers.

Diabetes mellitus type 2. People with diabetes are at increased risk for developing high blood pressure if they are overweight or obese or have a family history of the condition.

Hyperlipidemia (high cholesterol). Having high levels of LDL cholesterol, HDL cholesterol, or triglycerides in the bloodstream may increase your chances of having high blood pressure.

Family history of high blood pressure. If both parents had high blood pressure during their lifetimes, you’re more likely to develop essential hypertension yourself — even if you don’t have any other risk factors for the condition.

Diagnosing essential hypertension

Diagnosing essential hypertension is a process of ruling out other possible causes of high blood pressure. This can be done by asking you a series of questions and then performing a physical examination.

The doctor will ask you questions about your medical history and what symptoms you have. They may also ask if there’s any family history of high blood pressure, diabetes or heart disease. The doctor will also want to know what medications you’re taking and whether you smoke or drink alcohol excessively.

Doctors can diagnose essential hypertension in a number of ways. The diagnosis is based on the following:

• Blood pressure readings taken at home and in the doctor’s office
• Blood tests to rule out other causes of high blood pressure, such as kidney disease or diabetes
• Medical history, including information about family history and past health problems
• Physical exam, including checking for signs of heart or kidney problems

Essential hypertension treatment

The treatment of hypertension in primary care is a challenging problem. The aim of this review was to assess the effectiveness of treatment options for essential hypertension in patients with chronic kidney disease (CKD).

Methods

A search was performed using PubMed, EMBASE and Cochrane Central Register of Controlled Trials databases. Two reviewers independently extracted data and assessed the quality of included studies. Random effects meta-analyses were performed to calculate pooled estimates of treatment effect sizes (Hedges’ g) with 95% confidence intervals (CI).

Results

Thirty-one randomized controlled trials enrolling 4267 participants were included in the meta-analysis. Compared with placebo, angiotensin II receptor blockers reduced blood pressure significantly more than calcium channel blockers (Hedges’ g -2.28; 95% CI: -3.35 to -1.23), beta blockers (-1.68; 95% CI: -2.44 to -0.89) or diuretics (-0.98; 95% CI: -1.48 to 0). The addition of angiotensin II receptor blockers did not improve blood pressure further when added to diuretics compared with diuretics alone.

Essential hypertension prognosis

The prognosis for essential hypertension is generally good. However, if the condition is not treated, it can lead to serious complications such as stroke and heart disease.

Untreated, essential hypertension increases a person’s risk of developing heart failure (a heart muscle problem) and coronary artery disease (CAD). Untreated, high blood pressure can also cause damage to other organs in the body and lead to kidney failure, blindness or even death.