A low blood pressure of 45 mmHg is not normal and is considered hypotension. Normal blood pressure is defined as systolic blood pressure <120mmHg and diastolic blood pressure <80mmHg. When systolic blood pressure is <90mmHg and diastolic blood pressure <60mmHg, it is defined as hypotension; when systolic blood pressure is ≥140mmHg and or diastolic blood pressure ≥90mmHg, it is defined as hypertension. Low blood pressure can occur in normal people with a weak constitution. If the low pressure is 45 mmHg and there are no symptoms of hypoperfusion of the heart, brain, or kidneys caused by hypotension, no pharmacological intervention can be used. If there are manifestations of hypoperfusion caused by hypotension, such as dizziness, dizziness, weakness, blurred vision, memory loss, etc., drug treatment is recommended. Usually, the diet is appropriately salty, increase the sodium intake, and pay attention to exercise. In addition, with a low pressure of 45mmHg, it is recommended to check thyroid function to see if hypothyroidism may cause hypotension.