Low Diastolic Blood Pressure

When blood flows through the blood vessels, it exerts a pressure on their walls. This is known as blood pressure, which, for a normal healthy individual should be 120/80. The upper value is the measure of systolic pressure, while the lower value is the measure for the diastolic pressure. Blood pressure is always expressed as systolic/diastolic pressure. The systolic blood pressure is the pressure that the circulating blood exerts on the arterial wall, when the heart contracts to pump blood into the arteries. On the other hand, diastolic pressure is the pressure with which the circulating blood pushes against the arterial wall, when the heart relaxes after a contraction.

The value of diastolic pressure is always lower than the value of systolic blood pressure. When the diastolic pressure is too low, it is known as low blood pressure or hypotension. Usually, when the diastolic pressure is 60 mm Hg or less, it is considered as low blood pressure. Similarly, when the systolic pressure is 90 mm Hg or lower than that, it is also considered as low blood pressure. Low diastolic blood pressure can be caused by various factors and this condition can cause certain health problems in the long run.

Causes

Blood pressure, both systolic and diastolic, change over time. The diastolic pressure usually rises till midlife, after which it falls. So, for the elderly, a slight drop in diastolic blood pressure is regarded as quite normal. This is because, with age, the aorta stiffens and so, there is less blood available in the arteries when the heart relaxes. Other causes of stiffening arteries are arteriosclerosis and diabetes. Another important cause for low diastolic pressure in the elderly is the use of medications to lower a high systolic blood pressure.

Apart from these, a low diastolic pressure can be caused by dehydration, significant loss of blood, severe infection, nutritional deficiency which can result in hypoglycemia (low blood sugar), and anaphylaxis, which is a severe allergic reaction. Heart problems can also lower the diastolic pressure. Slow heart rate, heart failure and pulmonary embolism are some of the important heart conditions that can lower diastolic blood pressure. Both systolic and diastolic blood pressure in pregnant women can fall during the middle of pregnancy, i.e. around 24 weeks of pregnancy. This is however not a cause for concern, and the blood pressure usually returns to its normal level after delivery.

Symptoms

When the diastolic pressure is too low, the supply of oxygen and nutrients to the body cells reduces. A low diastolic pressure also impedes the removal of waste matter from the cells. This can eventually cause the death of cells. A small drop in diastolic blood pressure may not produce any symptom at times. Sometimes, in the case of a sudden fall in diastolic blood pressure, one can observe symptoms like dizziness or lightheadedness, nausea, blurred vision, thirst, cold and pale skin, rapid and shallow breathing, and fainting.

Treatment

An occasional slight drop in diastolic blood pressure that produces no or only mild symptoms does not require any treatment. However, a consistently low diastolic pressure needs to be properly evaluated by a physician, as it could be a sign of some major health problem. Treatment for such a condition depends on the underlying causes or factors that lower diastolic pressure.

Low diastolic blood pressure has been found to be associated with an increased risk for cardiovascular diseases and development of hardened arteries. Therefore, it is very important to keep track of diastolic blood pressure. Diastolic blood pressure readings maintained in the form of a low diastolic blood pressure chart can help in this regard. If the diastolic blood pressure is persistently low, then it is better to seek medical help.