Why low blood pressure is dangerous

Low blood pressure can cause
brain damage.High blood pressure is dangerous to health because it can cause kidney failure, and shorten lifespan. Likewise, low blood pressure (hypotension) is dangerous as it can cause life-threatening ailments, reports Muda Oyeniran.

Most of us dread to have high blood pressure or what is generally known as hypertension. This is because it is a common knowledge that hypertension is a killer disease.

Apart from the fact that hypertension on its own can kill, it may also lead to kidney failure, heart disease and other problems. However not many of us are aware that low blood pressure or what is known in medical parlance as hypotension can equally be harmful. According to medical experts, low blood pressure can cause dizziness and fainting. It also is an indication of serious heart disease, endocrine or neurological disorders. Findings also revealed that severe low blood pressure can deprive the brain and other vital organs of oxygen and nutrients, leading to a life-threatening condition called shock.

Further findings revealed that low blood pressure can also signal an underlying problem especially when it drops suddenly or is accompanied by signs and symptoms such as dizziness, fainting, lack of concentration and rapid or shallow breathing. What then is low blood pressure? Some experts defined low blood pressure as readings lower than 90 systolic or 60 diastolic. Systolic pressure is the first number in a blood pressure reading, which is the amount of pressure the heart generates when pumping blood through the arteries to the rest of the body. Diastolic pressure on the other hand is the second number in a blood pressure reading which refers to the amount of pressure in the arteries when the heart is at rest between beats.

However, some experts say this could be misleading because what is considered low blood pressure for one individual may be normal for another person. Commenting on the issue, a Consultant Cardiologist with the Lagos State University Teaching Hospital (LASUTH), Dr. Shittu Gbadamosi disclosed that low blood pressure is hard to quantify. According to him, blood pressure is not static as it can vary considerably in a short amount of time depending on body position, breathing rhythm, stress level, physical condition, the medications one take, what one eat and drink and the time of the day. He also stated that blood pressure is usually lowest at night and rises sharply on waking.

According to the expert, doctors usually consider a patient’s blood pressure to be too low only if it causes noticeable symptoms. He revealed that a sudden fall in blood pressure can be dangerous. “A change of just 20mmHg, that is, a drop from say like 130 systolic to 110 systolic, for example, can cause dizziness and fainting when the brain fails to receive an adequate supply of blood. In some instances, low blood pressure can be a sign of serious and even life-threatening disorders.

He listed pregnancy, medications, heart problems, endocrine problems, dehydration, blood loss, severe infection (septicemia), allergic reaction (anaphylaxis) and nutritional deficiencies as possible causes of low blood pressure.

According to him, a woman’s circulatory system expands rapidly during pregnancy leading to a likely drop in her blood pressure. He further revealed that during the first 24 weeks of pregnancy, systolic pressure commonly drops by five to 10 points and diastolic pressure by as much as 10 to 15 points.

“Many drugs including diuretics and other drugs that treat high blood pressure; heart medications such as beta blockers; drugs for Parkinson’s disease; narcotics and alcohol can cause low blood pressure. Also, heart conditions including extremely low heart rate, heart valve problems, heart attack and heart failure may also cause low blood pressure because they prevent the body from being able to circulate enough blood,” he explained.

He also emphasized dehydration and loss of blood as major factors causing low blood pressure. “When you become dehydrated, your body loses more water than it takes in. Even mild dehydration can cause weakness, dizziness and fatigue. Fever, vomiting, severe diarrhoea, over use of diuretics and strenuous exercise can all lead to dehydration.

Similarly, losing a lot of blood from major injury or severe internal bleeding reduces the amount of blood in your body leading to a severe drop in blood pressure,” he added Dr Gbadamosi also revealed that anaemia which may result from lack of vitamins B-12 and folate could lead to low blood pressure.

In his own submission, a consultant physician at the Lagos University Teaching Hospital (LUTH), Dr. Kola Owolabi attributed certain types of low blood pressure to age. According to him, drops in blood pressure on standing or after eating occur primarily in older adults.

He stated that moderate forms of low blood pressure can seriously affect an individual’s quality of life leading not only to dizziness and weakness, but also to fainting and a risk of injury from falls. “Severely low blood pressure from any cause can deprive your body of enough oxygen to carry out its normal functions, leading to damage to your heart and brain,” he stated.

According to Dr. Owolabi, the appropriate therapy for low blood pressure would depend on the underlying cause, adding that doctors usually try to address the primary heath problem such as dehydration, heart failure and so on rather than low blood pressure itself.

“When low blood pressure is caused by medications, treatment usually involves changing the dose of medication or stopping it entirely. If it is not clear what is causing low blood pressure or no effective treatment exists, the goal is to raise your blood pressure and reduce signs and symptoms,” he explained.

On how a person having low blood pressure can have his blood pressure raised, Dr Owolabi offers the following advice: “Use more salt. Experts usually recommend limiting the amount of salt in your diet because sodium can raise blood pressure, but for people with low blood pressure, this can be a good thing, although excess sodium can also lead to heart failure. The affected person should also drink more water because fluids increase blood volume and help prevent dehydration. The affected person should also stay away from alcohol because alcohol dehydrates. Apart from all these, such an individual should follow a healthy diet.