Hypertension

Hypertension, or high blood pressure, is a medical condition in which the pressure of blood increases in blood vessels. Hypertension can be classified as either primary, when there is no obvious cause, or the much less common secondary hypertension, where there is an identifiable cause.

A blood pressure of 140/90 mmHg or higher is considered high. Both numbers are important. If one or both numbers are consistently high, you have high blood pressure or hypertension. Even if treatment brings your readings into the normal range, you are still considered hypertensive.

Types of Hypertension

Hypertension is divided into two subtypes:

• Primary or Essential Hypertension: About 90–95% of cases of hypertension are primary, meaning that the high blood pressure is due to nonspecific lifestyle and genetic factors. Lifestyle factors that increase the risk include excess salt in the diet, excess body weight, smoking, and alcohol use.
• Secondary Hypertension: The remaining 5–10% of cases are categorized as secondary hypertension, defined as high blood pressure due to an identifiable cause or underlying disease.

Causes of Hypertension / High Blood Pressure

Hypertension occurs when the arterioles, small blood vessels that branch off from the arteries, become constricted, making it difficult for blood to pass through them. This results in elevated blood pressure and forces the heart to work harder. If blood pressure at rest remains at 140/90 mmHg or higher, hypertension is likely.

Blood pressure is determined by the volume of blood pumped by the heart and the size and condition of the arteries. Many factors can affect blood pressure, including:

• Volume of water in the body
• Salt content in the body
• Condition of the kidneys, nervous system, or blood vessels
• Hormone levels in the body

Essential hypertension has no identifiable cause but is thought to involve genetic and environmental factors such as salt intake. It makes up more than 95% of all cases of high blood pressure.

Secondary hypertension is caused by another disorder, such as:

• Adrenal gland tumors
• Cushing’s syndrome
• Kidney disorders
• Glomerulonephritis (inflammation of the kidneys)
• Renal vascular obstruction or narrowing
• Renal failure
• Use of medications, drugs, or other chemicals
• Oral contraceptives
• Periarteritis nodosa
• Atherosclerosis
• Embolus in blood vessels
• Fibromuscular dysplasia
• Polyarteritis nodosa
• Pyelonephritis
• Polycystic disease
• Wilms tumor
• Diabetes mellitus
• Renal artery stenosis
• Coarctation of the aorta
• Excessive use of steroids, oral contraceptives, cyclosporine
• Toxemia of pregnancy
• Lead poisoning
• Raised intracranial pressure

Symptoms of Hypertension / High Blood Pressure

In most cases, hypertension does not present any symptoms. Occasionally, a mild headache may occur. However, if you experience any of the symptoms below, you should see a doctor immediately, as they may indicate dangerously high blood pressure (malignant hypertension) or complications from high blood pressure.

• Headache
• Dizziness
• Blurred vision
• Epistaxis (nosebleeds)
• Anxiety
• Nausea
• Vomiting
• Red face and skin (flushing)
• Increased swelling
• Diplopia (double vision)
• Flushes of heat
• Dyspnea (difficulty breathing)
• Palpitations
• Tremors
• Fatigue
• Drowsiness
• Irritability
• Angina-like chest pain (crushing chest pain)
• Blood in urine
• Irregular heartbeat
• Ear noise or buzzing