The diagnostic criteria for hypotension are that if both systolic and diastolic pressures are below normal levels, it is diagnosed as hypotension. Normal blood pressure ranges from 90-140 mmHg for systolic and 60-90 mmHg for diastolic. A clinical diagnosis of hypotension is made if the systolic pressure is below 90 mmHg and diastolic pressure is below 60 mmHg. There are many causes of hypotension, which can result from certain diseases, blood loss, anaphylactic shock, heart failure, etc. Hypotension can also be caused by physiological reasons such as an unreasonable diet structure, lack of nutrition, or lack of energy. Regardless of the cause, any instance of hypotension requires appropriate treatment.