Nine years ago, my grandfather died because of low blood pressure. He was feeling unwell and had gone to a clinic, where the doctor found out his blood pressure was low. He was given tablets to help him until the next day when the doctor would review his status. Unfortunately, he died the next day.
Dr Anthony Makhoba, a physician at Nsambya Hospital says low blood pressure, known as hypotension, occurs when the blood pressure during and after every heartbeat, is lower than normal. When this occurs, the heart, brain, kidney and other parts of the body do not get enough blood and oxygen.
Blood pressure is expressed as systolic (the contraction of the heart, during which blood is pumped into the arteries) over diastolic (expansion of the chambers of the heart at each heartbeat, during which they fill with blood).
For an adult, a normal systolic blood pressure ranges between 90mmHg to 140 mmHg and the normal diastolic pressure ranges between 60mmHg to 90 mmHg. A correct reading is obtained when the patient is calm as anxiety may lead to a false reading.
If the systolic blood pressure has gone below 90 mmHg and the diastolic is below 60mmHg (90/60), it is low. “At this stage, the organs like the kidney, brain and heart will fail to work normally and it can easily progress to death,” Dr Makhoba notes.
Causes and risk factors
Large volume blood loss due to severe bleeding, which reduces the amount of blood for the heart to pump through the body, diarrhoea, extreme sweating without replacement of fluids can also lead to low blood pressure.
Other causes include sepsis (severe blood infection), pneumonia (chest infection), meningitis (brain infection), urinary tract infections, severe malaria, heart problems, endocrine disorder, massive pulmonary embolism (clot lodged in the lungs) and anaphylaxis (when a person reacts to particular agents like drugs and foods).
Symptoms and signs
These will depend on the underlying cause but in most cases it starts with fainting, light headedness or dizziness, and sweating when the body is cold. It is because the body is fighting to maintain a normal blood pressure and divert blood to vital organs.
“Some people are restless and drowsy because the brain is not getting enough blood to keep it alert and in most cases the pulse rate is quite high (more than 100 beats per minute) because the heart is pumping hard to maintain the smooth running of the body,” he notes.
Diagnosis can only be made by medical personnel. It is after checking the blood pressure and other symptoms that a doctor will know one has low blood pressure and embark on other examinations and laboratory tests to ascertain the cause.
Nsambya hospital statistics indicate that about 20 cases of low blood pressure are recorded on average every month.
Unlike high blood pressure, Dr Makhoba says LBP is quite dangerous because the body has a particular blood pressure, within which the blood is supplied to the body.
In most cases, the organs will not get enough blood to function if the blood pressure is low. He notes that in the process, the important organs will fail thus leading to death if not corrected urgently.
One is given treatment depending on the underlying cause. For the body to maintain a right blood pressure, one needs the right volume of blood.
Here, people need to take in fluids like water, tea, juice or soup to replace the fluids lost daily through sweat and urine.
Dr Makhoba says blood pressure is only measured with a sphygmomanometre and should be used by a qualified health worker.
He encourages routine medical checkups to help people know their health status. Whenever one experiences any of these symptoms, they should seek medical attention immediately.