The correct expression for a low pressure of 100 and a high pressure of 140 is 140 mmHg systolic and 100 mmHg diastolic. a low pressure of 100 and a high pressure of 140 is considered moderate hypertension. Moderate hypertension requires initiation of oral antihypertensive drug therapy, along with lifestyle improvement, treatment of comorbidities, and control of risk factors. According to the guidelines, hypertension is diagnosed if the systolic blood pressure is ≥140 mmHg and/or diastolic blood pressure is ≥90 mmHg when the blood pressure is measured once a day for three days, respectively, in the absence of antihypertensive 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. Hypertension was further classified into three levels according to the level of elevated blood pressure. Class I hypertension (mild) was 140-159 mmHg systolic and 90-99 mmHg diastolic; Class II hypertension (moderate) was 160-179 mmHg systolic and 100-109 mmHg diastolic; Class III hypertension (severe) was ≥180 mmHg systolic and ≥110 mmHg diastolic. The above criteria were applied to men and women over 18 years of age. For children, the 95% median of blood pressure values in different age groups, which are usually lower than adult levels, are used. Therefore, to determine whether a patient with a low pressure of 100 and a high pressure of 140 is hypertensive and which level of hypertension he or she belongs to, the age of the patient needs to be taken into account. A low pressure of 100 and a high pressure of 140 is considered moderate hypertension and must be treated with oral antihypertensive medication, along with lifestyle improvement and risk factor control. Medication and lifestyle improvement need to be carried out at the same time, and cannot rely on medication alone.