Low blood pressure

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By Dr. Fasiha Hasham

The heart is the most essential organ of the body, continuously pumping blood to maintain body`s vital functions. With each heart beat the heart expands and contracts, pushing the blood in to the blood vessels. Blood pressure can be defined as the pressure exerted by the blood on the vessel wall as it enters the circulatory vessels.

Blood pressure is measured in a ratio, the upper or the systolic pressure, shows the maximum pressure that is exerted when the heart pumps blood into the circulation. The second number is the diastolic pressure, which shows the pressure when the heart relaxes between the contraction. Normally the blood pressure is 120/ 80 mmHg or less.

Blood pressure is usually lowest during sleep or resting and highest during exercise or emotional stress. Low blood pressure usually involves systolic readings of 90 mmHg or less.

Some of the symptoms which the patient experiences while having low blood pressure are feeling of faintness, mental disorientation, blurred vision and seizures

Blood pressure may fall suddenly when a person is rising from lying or sitting position, this is called orthostatic hypotension. It usually occurs in elderly people, and is usually caused by medications, usually the ones to treat high blood pressure. A complication of diabetes, diabetic neuropathy can cause low blood pressure. It can also result from a shock, a medical emergency that can be a result of severe burns, injuries, excessive blood loss, a heart attack or stroke.

In case of low blood pressure treatment depends on the underlying cause, for example orthostatic hypotension, it is a side effect of medications, so it can be treated by adjusting the dose or prescribing an alternative medication.

Another example is shock, which is a medical emergency; in this condition blood pressure is so low that there is not sufficient blood flow to the peripheral tissues. So the treatment involves the administration of intravenous fluids to sustain life.

Blood pressure is measured by an instrument called sphygmomanometer, which consists of an inflatable rubber cuff attached to a measuring gauge. The cuff is wrapped around the upper arm and inflated, compressing a large artery thus stopping the flow through the lower arm. The air is thus released from the cuff and the doctor listens to the flow of blood as it passes through the artery with the help of a stethoscope and measures it on the gauge, which corresponds to the systolic blood pressure.

If the blood pressure is very low the doctor will take a complete medical history and will request blood tests to find out the underlying cause and treat it accordingly.

Important notes

• Avoid sudden movement such as jumping out of bed in the morning, take one to two minutes first to sit and then to stand.
• A person with diabetes should make every effort to avoid complications by keeping the diabetes under control.
• Anyone taking medications for high blood pressure should report any episode of fainting or dizziness to the doctor.
• Hypotension due to shock can be fatal and should be treated urgently.

 Editor’s Note: Dr. Fasiha Hasham obtained her medical degree from Sindh Medical College and completed a residency at Jinnah Post Graduate Medical Centre in Pakistan before moving to the United States. Her specialties include Internal Medicine and Gynecology and Obstetrics. She is married with four children and lives in Farmington Hills, Michigan. The views expressed here are her own.