The correct expression for high pressure 140 and low pressure 90 is 140 mmHg systolic and 90 mmHg diastolic. high pressure 140 and low pressure 90 is considered mild hypertension. Hypertension is diagnosed if systolic blood pressure is ≥ 140 mmHg and/or, diastolic blood pressure is ≥ 90 mmHg when blood pressure is measured once a day for three days respectively without the use of anti-hypertensive medication. Patients with a previous history of hypertension, who had received regular blood pressure lowering treatment, were diagnosed with hypertension despite a blood pressure <140/90 mmHg. In a population with a continuous normal distribution of blood pressure levels, there is no clear line of demarcation between normotension and elevated blood pressure, and the criteria for hypertension are defined based on clinical and epidemiological data. Hypertension is further classified into three levels according to the level of elevated blood pressure. Class I hypertension (mild, for systolic blood pressure 140-159 mmHg and diastolic blood pressure 90-99 mmHg; Class II hypertension (moderate, for systolic blood pressure 160-179 mmHg and diastolic blood pressure 100-109 mmHg; Class III hypertension (severe, for systolic blood pressure ≥180 mmHg and diastolic blood pressure ≥110 mmHg. The above criteria apply to men and women over 18 years of age. For children, the 95th percentile of blood pressure values for different age groups, usually lower than adult levels, is used. Mild hypertension needs to be treated by lifestyle improvement, treatment of comorbidities, and control of risk factors, and if this does not work for six months, drug therapy needs to be initiated. Patients with a high number of cardiovascular risk factors or comorbidities with other cardiovascular diseases require early initiation of antihypertensive therapy.