(arterial hypertension) is condition of high blood pressure. Blood pressure is the pressure (tension) of blood on arterial wall which depends of many factors such as power of heart muscle contraction, blood volume and especially artery resistance to blood. Blood pressure can be measured in millimeters of mercury (mmHg) and it consists of two digits. For example 120/75. This can be said as "120 over 75", where 120 is pressure when heart contracts and 75 is the same pressure when heart is resting between contractions.
Hypertension is very dangerous because it increases chances of developing other heart diseases such as stroke, heart attacks, heart failure e.t.c

There are two types of Hypertension: primary - essential and secondary. Hypertension can be considered essential when there are not any specified causes which can explain patient's high blood pressure, and secondary is when those causes exist (such as kidney diseases, some types of tumor, e.t.c).
Normal blood pressure level is 120/80. Blood pressure between 120/80 and 139/89 can be described as "prehypertension". Although this condition isn't state of disease, persons with this level of blood pressure have more chances of developing hypertension.

There are many factors that can be cause of Hypertension. Some of these are stress, occupation, obesity, overmuch salt intake (the most common cause), alcohol, smoking, too much noise exposure. Also hypertension is genetic kind of disorder. During pregnancy up to 10% of women develop hypertension.

Symptoms of hypertension are fatigue, headaches, facial flush, although its rarely serious enough to develop symptoms. The most common way of discovering hypertension is during routine medical checkups.

There are many classes of medications for hypertension called antihypertensives but in the most cases it can be reduced by changing lifestyle, including proper diets, reducing salt intake, exercises resulting weight loss, discontinuing smoking and reducing level of daily stress.