Causes of Hypotension

Low blood pressure is something that’s beneficial, wouldn’t you think? In most cases, it certainly is. But when low blood pressure becomes undesirably low, then that’s a cause for alarm. First, let’s take a look at what we mean by low blood pressure to understand it better.

What Is Low Blood Pressure Or Hypotension?

Blood pressure is the force exerted by your blood against the walls of the blood vessels. Your blood pressure is expressed as two numbers which are a measure of the systolic and diastolic blood pressure. The systolic blood pressure represents the pressure generated by the muscle of the heart contracting and pumping blood into the arteries. The diastolic blood pressure represents the pressure in the arteries as the heart rests between contractions.

Blood pressure is always higher when the heart is pumping than when it is relaxing. Normal systolic blood pressure ranges between 90 and 120 mm Hg. Normal diastolic blood pressure falls between 60 and 80 mm Hg.

An optimal blood pressure level is a reading lower than 120/80 mm Hg. A high blood pressure level indicates a reading over 140/90 mm Hg. Unlike high blood pressure, low blood pressure is diagnosed by the signs and symptoms of low blood flow rather than a specific blood pressure level.

Basically, low blood pressure is when the flow of blood is too low to deliver enough oxygen and nutrients to vital organs such as the brain, heart, and kidney. In this situation, the organs cannot function normally and may be temporarily or permanently damaged.

If your blood pressure level is low and yet you show no signs or symptoms, it means you do not have low blood pressure and don’t require treatment. On the other hand, if you develop symptoms like dizziness, fainting, fatigue, blurred vision or confusion, it is an indication of low blood pressure or hypotension.

Let’s understand the different types of hypotension and what causes low blood pressure in each case.

What Are The Types Of Hypotension?

When someone rises quickly from a sitting or lying down position, they may experience a sudden drop in blood pressure. On standing up, blood generally pools to the lower extremities as a result of the effects of gravity. Normally, the body compensates for this drop in blood pressure by signalling the heart to beat faster and, in turn, constrict the blood vessels. However, if the cardiovascular and nervous system fails to react or reacts too slowly, it results in a type of low blood pressure known as postural or orthostatic hypotension which can lead to fainting.

A type of low blood pressure known as neurally mediated hypotension can occur when someone stands for an extended period of time. Falling unconscious as a result of this is termed as vasovagal syncope.

Dizziness and black outs after eating (especially after consuming heavy-carb meals) are believed to be caused by blood settling in the vessels of the stomach and intestine, which is another type of hypotension.

Here’s a look at the causes of hypotension.

What Are The Causes Of Low Blood Pressure?

These are the common conditions that can cause low blood pressure:

• Ageing

  The natural changes in the body as a result of ageing can increase the risk of both low and high blood pressure. Plaque build-up in blood vessels that occurs with age can impact the blood flow to the heart muscle and the brain.

• Pregnancy

  Blood pressure may drop during pregnancy as the circulatory system expands rapidly. The blood pressure usually returns to the pre-pregnancy level post-birth.

• Heart Problems

  An extremely low heart rate (bradycardia), heart valve problems, a heart attack and heart failure can cause low blood pressure.

• Endocrine Disorders

  Thyroid conditions such as parathyroid disease, adrenal insufficiency (Addison’s disease), low blood sugar (hypoglycemia) and, in some cases, diabetes can contribute to low blood pressure.

• Dehydration

  Fever, vomiting, severe diarrhoea, overuse of diuretics and physical overexertion can cause dehydration. Dehydration can lead to weakness, dizziness and fatigue.

• Blood Loss

  Blood loss from a major injury or internal bleeding, reduces the amount of blood in your body, leading to fall in blood pressure levels.

• Severe Infection (Septicemia)

  When an infection in the body enters the bloodstream, it can cause a lethal drop in blood pressure and send your body into a septic shock.

• Severe Allergic Reaction (Anaphylaxis)

  Certain foods, medications, insect venoms and latex can trigger an allergic reaction (anaphylaxis) that can result in breathing problems, hives, itching, a swollen throat and a deadly drop in blood pressure.

• Nutrient Deficiency

  Lack of food or a deficiency of vitamins B-12 and folate in the body can result in anaemia and low blood pressure.

A few medications that can cause low blood pressure, include:

• Diuretics
• Alpha-blockers
• Beta-blockers
• Drugs for Parkinson’s disease
• Antidepressants
• Drugs for erectile dysfunction

When Should You Be Concerned About Low Blood Pressure?

If you experience any health symptoms along with a blood pressure level reading that’s lower than normal, do consult your doctor at once.

The first step to diagnosing low blood pressure is to compare your blood pressure in both the lying (supine) and standing positions. For an accurate diagnosis, note down the activity and the symptoms you faced at that time, before you visit your doctor.

Low blood pressure or hypotension is only a cause for worry if it drops low enough to lead to the damage of your vital organs.

If you’d like to go through more such healthcare articles on hypertension or hypotension, or if you wish to book a consultation with an experienced practitioner, check our website.