Low Blood Pressure (Hypotension): Causes & Symptoms

The pressure exerted by flowing blood on the walls of blood vessels is called blood pressure. Low blood pressure, or hypotension, occurs when blood pressure falls below normal levels. Various factors contribute to hypotension, including dehydration, prolonged bed rest, and certain medications. Chronic low blood pressure can lead to dizziness, fainting, and fatigue. In some cases, it is harmless, but in others, it can lead to serious health issues. So, keep reading to learn what low blood pressure is, its causes, key symptoms, complications and effective treatment options. 

What is Low Blood Pressure?

Low blood pressure, medically called hypotension, occurs when blood pressure is below 90/60 mmHg. The condition is not always alarming, but it can result in severe consequences when blood flow to vital organs becomes insufficient.

Blood pressure is measured in millimeters of mercury (mmHg). The first number, systolic, refers to heart contractions. The second number, diastolic, measures the pressure when the heart relaxes.  The following table explains ideal blood pressure ranges based on activity levels and age groups:

Age Group	Normal Resting BP (mmHg)	Ideal BP During Moderate Activity (mmHg)	Ideal BP After Intense Workout (mmHg)
Children (6-12 yrs)	90/60 to 115/75	100/65 to 120/80	110/70 to 130/85
Teens (13-19 yrs)	105/65 to 120/80	110/70 to 130/85	120/80 to 140/90
Adults (20-40 yrs)	110/70 to 120/80	120/80 to 140/90	130/85 to 160/95
Adults (40-60 yrs)	115/75 to 130/85	125/80 to 140/90	135/85 to 160/95
Seniors (60+ yrs)	120/80 to 140/90	130/85 to 150/95	140/90 to 160/100

The body regulates blood pressure through the heart, kidneys, and blood vessels. If these systems are compromised, blood pressure might drop too low. Proper functioning ensures sufficient oxygen and nutrients reach the organs.

What Are the Symptoms of Low Blood Pressure

Low blood pressure, or hypotension, can appear with a range of symptoms from mild to severe. Some people might notice only occasional discomfort, while others may need medical attention to address low blood pressure symptoms that disrupt daily life. The most common ones are discussed as follows: 

1. Dizziness and Lightheadedness

Dizziness is one of the most common symptoms of low blood pressure, especially when standing up quickly after sitting or lying down. It occurs when the body can’t adjust blood flow fast enough, leading to lightheadedness or a spinning sensation. Dizziness can also be accompanied by fainting or weakness, particularly after prolonged standing or physical activity. These symptoms may signal a significant drop in blood pressure and if they persist or worsen, you must seek out medical attention.

2. Fainting

A significant drop in blood pressure can cause fainting, especially if blood flow to the brain is insufficient. This occurs when the brain doesn’t get enough oxygen and nutrients, momentarily causing a loss of consciousness. 

Fainting can also be preceded by warning signs such as dizziness, lightheadedness, or nausea which may help individuals recognize the onset of an episode. People who faint should consult a doctor, as it may indicate an underlying issue.

3. Fatigue

Feeling overly tired or fatigued can also be one of the symptoms of low blood pressure. When the blood pressure is too low, organs and muscles may not get enough oxygen-rich blood, which will lead to fatigue and decreased stamina. This feeling can persist even after a full night’s rest.

4. Blurred Vision

Low blood pressure can temporarily cause blurred or double vision. This results from an inadequate blood supply to the eyes, affecting visual clarity. Some people may experience a dim or shadowy effect in their vision, particularly when standing up quickly.

5. Nausea

Lower blood pressure may also lead to nausea, as reduced blood flow to the digestive system affects the stomach’s ability to function efficiently. This restriction causes nausea, which may be worsened by dizziness or lightheadedness.

2 Types of Low Blood Pressure Experienced by Many 

Blood pressure is regulated by various systems, including organs, hormones, and nerves. For instance, the autonomic nervous system triggers the “fight-or-flight” response, which signals the heart and other body systems to adjust blood pressure levels. Issues with the autonomic nervous system or related conditions can lead to decreased blood pressure. Consequently, hypotension is classified into different categories based on its timing and underlying causes:

1. Orthostatic Hypotension

Orthostatic hypotension is characterized by a sudden drop in blood pressure upon standing from a sitting or lying position. This condition occurs due to the body’s inability to adequately adjust blood flow and pressure, often leading to symptoms like dizziness, lightheadedness, and fainting. 

Diagnosis typically requires a blood pressure drop of at least 20 mmHg systolic or 10 mmHg diastolic within three minutes of standing.

2. Postprandial Hypotension

Postprandial hypotension refers to a decrease in blood pressure that occurs after eating. It particularly affects older adults or individuals with autonomic nervous system disorders. This condition arises when blood flow is redirected to the digestive system, leading to insufficient blood supply to other areas. This can result in dizziness and fainting. The symptoms can range from mild to severe and are exacerbated by large meals or specific health conditions.

Also read: Hyperventilation: Causes, Treatments, and Prevention

What Causes Low Blood Pressure?

Hypotension can result from various factors, both temporary and chronic. These can result in an insufficient supply of oxygen and nutrients to vital organs, such as the brain and the heart. Thus, when you know the main causes of hypotension, you can prevent it from turning into serious health concerns. Some of the main low blood pressure causes are as follows: 

• Dehydration

Dehydration occurs when the body loses more fluids than it takes in, which leads to a decrease in blood volume. This reduction can cause blood pressure to drop. As a result, it becomes difficult for the heart to circulate blood effectively. 

• Blood Loss

Severe bleeding, either due to trauma or internal disease, such as ulcers, severely reduces the amount of blood remaining in the body. This is hypovolemic shock and prevents tissues throughout the body from receiving an adequate supply of oxygen. 

Certain cancers, such as colorectal cancer, gastric cancer, and liver cancer, can cause internal bleeding, which contributes to hypotension. Additionally, a Mallory-Weiss tear, which is a tear in the lining of the esophagus due to severe vomiting, can also lead to significant internal bleeding and result in low blood pressure. 

• Medications

Certain medications, especially those used to treat high blood pressure and heart conditions, can inadvertently lower blood pressure too much. Diuretics, for example, increase urine production and fluid loss, which can reduce blood volume. 

Patients taking these medications must be monitored closely to avoid hypotension, which can cause dizziness and fainting spells if blood pressure drops significantly.

• Heart Conditions

Heart problems such as heart failure, cardiac arrhythmia, or a weakened heart muscle impair the heart’s ability to pump blood effectively. This inefficiency can lead to low blood pressure and poor circulation. When the heart cannot maintain adequate pressure, vital organs may not receive enough oxygen-rich blood.

• Allergic Reactions

Anaphylaxis is a severe allergic reaction that can cause a rapid drop in blood pressure. During this reaction, the body releases chemicals that dilate blood vessels excessively, leading to a condition known as shock. 

• Anxiety

Anxiety can cause a sudden drop in blood pressure (hypotension) because it triggers the body’s “fight-or-flight” response. This can lead to widened blood vessels, slowing blood flow. When blood doesn’t reach the organs quickly enough, it causes a drop in blood pressure and results in dizziness or weakness.

• Infections

Severe infections, such as sepsis, can cause septic shock, a life-threatening condition characterized by dangerously low blood pressure. In sepsis, bacteria release toxins into the bloodstream, which can damage blood vessels and interfere with the body’s ability to regulate blood pressure. As a result, blood flow to vital organs is reduced, resulting in serious symptoms like confusion, weakness, and even organ failure if not treated timely.

How To Raise Blood Pressure?

Several methods are available to stabilize low blood pressure. Treatments mainly focus on addressing the underlying causes and maintaining healthy circulation. So, how to increase blood pressure? The following are some of the strategies to raise blood pressure when it drops below normal levels: 

• Hydrate Frequently

Staying adequately hydrated is crucial for maintaining blood volume, which directly influences blood pressure. Dehydration can lead to reduced blood volume, causing hypotension. Drinking water and electrolyte-rich fluids ensures optimal circulation and prevents symptoms like dizziness and fainting associated with low blood pressure.

• Moderate Consumption of Caffeine

One effective method of raising blood pressure is moderate consumption of caffeine. Drinks like coffee, tea, or energy drinks can temporarily boost blood pressure by narrowing blood vessels and increasing heart rate. However, it’s important not to overdo it, as too much caffeine can lead to other health issues. Always consult a healthcare professional for personalized advice on managing blood pressure.

• Intake of More Salt

Increasing dietary salt can help elevate blood pressure by promoting water retention in the body. Sodium maintains fluid balance; however, this approach should be monitored by a healthcare professional to avoid excessive intake, which could lead to hypertension or other health issues.

• Wearing Compression Stockings

Compression stockings exert pressure on the legs, which in turn prevents blood from pooling and thereby enhances return venous flow to the heart. This method is particularly beneficial for individuals with orthostatic hypotension, as it helps maintain stable blood pressure during standing or prolonged sitting.

• Adjust Medications

If low blood pressure is a side effect of certain medications, consulting a healthcare provider about adjusting dosages or switching medications may be necessary. Proper management ensures that the benefits of medication are maintained while minimizing adverse effects on blood pressure.

• Small Frequent Meals

To mitigate postprandial hypotension, where blood pressure drops after large meals, you should take smaller, more frequent meals. This approach reduces the workload on the digestive system and prevents significant fluctuations in blood pressure, thereby minimizing symptoms like lightheadedness after eating.

What To Do If You Have Symptoms of Low Blood Pressure?

If you feel symptoms like dizziness, faintness, or light-headedness, sit down or lie down immediately to prevent falls and give your body a chance to stabilize. These symptoms indicate that blood pressure may have dropped too low, which means vital organs like the brain aren’t receiving enough oxygen and nutrients. 

• In severe cases, low blood pressure can lead to shock, a medical emergency that demands immediate attention. Signs of shock include cold and clammy skin, rapid and shallow breathing, bluish skin tone, or a weak and rapid pulse. If you or someone nearby shows these signs, call 9-1-1 right away to get help.
• For ongoing symptoms, speak with your doctor, who may perform a blood pressure test to diagnose low blood pressure. Depending on your symptoms, additional tests, such as blood and urine analyses, imaging tests, or a tilt table test, may help identify the main cause. 

Managing symptoms early is essential, and learning basic life support skills can be invaluable if someone near you experiences a sudden drop in blood pressure or shock.

Also Read: What Is Carotid Pulse? A Comprehensive Guide

Complications of Low Blood Pressure

Untreated low blood pressure can lead to complications, particularly when blood flow remains low for extended periods. When people are aware of these risks, they can prevent severe health issues. Some of the complications resulting from low blood pressure are: 

• Oxygen Starvation to Organs

Chronic low blood pressure can reduce oxygen supply to vital organs like the brain, heart, and kidneys. If these organs don’t receive adequate oxygen over time, they can sustain damage, potentially leading to organ failure. This is especially concerning for individuals with prolonged hypotension.

• Risk of Falls

Frequent dizziness or fainting episodes significantly increase the risk of falls, especially in older adults. Falls due to hypotension can cause fractures, head injuries, and other serious health complications that may affect mobility and quality of life.

• Heart Damage

In some cases, prolonged hypotension can strain the heart as it works harder to circulate blood. This extra workload can gradually weaken the heart, leading to damage or worsening conditions in those with existing cardiovascular issues.

• Cognitive Issues

When blood pressure remains low, the brain may not receive enough oxygen-rich blood, causing cognitive issues. This can lead to memory problems, confusion, and difficulty concentrating, particularly in older adults or those with prolonged hypotension.

• Shock

Shock is a serious complication of low blood pressure. It occurs when the body doesn’t get enough blood flow to function properly. A lack of oxygen can damage vital organs, like the heart and brain. Symptoms of shock include confusion, weak pulse, rapid breathing, and cold, clammy skin. Therefore, people should seek immediate medical attention to prevent further harm.

Managing Low Blood Pressure for a Better Quality of Life!

Low blood pressure can become a problematic issue when it causes symptoms or affects organ function. Therefore, you should identify your underlying conditions, stay hydrated, and make simple lifestyle adjustments to improve blood pressure levels. 

Regular monitoring, especially for those at risk, is essential for maintaining optimal health and preventing complications. When people manage low blood pressure, they can maintain a healthy, active lifestyle, free from the risks associated with hypotension.