There are many reasons for low blood pressure like hypoglicemia, low or very little menstruation for females or manopose, hunger for 12-14 hours, problems with thyroid glands, mental diseases like tension and others, sleep pills, contraceptive pills, internal bleeding in any part of the body, depression or emotional shock or lack of hard work or routine body excercise.
When your systolic blood pressure is around 90 or below and if your diastolic blood pressure is around 70 or below then the this condition is considered as low blood pressure. Always remember that low blood pressure is not any kind of disease its a type of condition, which can be cured after taking few important steps. Low blood pressure reflects the strength of your hearth and veins. With few excercise or by consuming exciting products like coffee or tea can bring this stage to normal.