Essential hypertension - elevated blood pressure with no underlying identifiable cause - is the most common type of hypertension. It is also by far the most common cardiovascular disorder in the general population. The prevalence of hypertension increases with age, so that 90% of people develop essential hypertension over their lifetime. The exact cause of essential hypertension is still unknown, and it is also called idiopathic or primary hypertension. However, there is good evidence that multiple factors - both genetic and environmental - are involved. Hypertension does not cause any immediate subjective problems. Therefore, it can remain undetected for years, but it is a significant risk factor for heart attack, stroke, atrial fibrillation, and other cardiovascular diseases.

It seems that one of the leading causes of essential hypertension is increased salt intake. Excess salt, or more precisely sodium, retains water in the circulatory system, increasing blood pressure. Several studies have found that daily salt intake greater than 100 mmol (approximately 5.9 g) is a risk factor for developing hypertension. The problem is that nowadays, the vast majority of people exceed this limit. 

World Health Organization (WHO), in its guideline “Sodium Intake for Adults and Children”, strongly recommends daily salt intake for adults less than 5 g. Estimated salt intake in Europe (1990-2009) is 8-12 g/day, which is very high and can, to some extent, explain the prevalence of hypertension in the general population.