Understanding Low Blood Pressure: Causes, Symptoms, Risks

What is Considered Low Blood Pressure?

Blood pressure is recorded with two numbers - the systolic pressure (top number) and diastolic pressure (bottom number). Normal blood pressure ranges are:

• Normal: Less than 120 mmHg systolic AND less than 80 mmHg diastolic
• Elevated: 120-129 mmHg systolic AND less than 80 mmHg diastolic
• Stage 1 Hypertension: 130-139 mmHg systolic OR 80-89 mmHg diastolic
• Stage 2 Hypertension: 140 mmHg or higher systolic OR 90 mmHg or higher diastolic
• Hypotension: Less than 90 mmHg systolic OR less than 60 mmHg diastolic

As the criteria shows, low blood pressure is defined as a systolic pressure below 90 mmHg and/or a diastolic pressure below 60 mmHg. Some experts also consider blood pressure under 100/60 as hypotension, even if it doesnt strictly meet the technical thresholds.

Symptoms of Low Blood Pressure

Many people with low blood pressure are asymptomatic and dont experience any concerning symptoms. However, some common symptoms can include:

• Dizziness or lightheadedness
• Fainting (syncope)
• Lethargy, weakness, or fatigue
• Blurred vision
• Nausea
• Depression
• Cold, clammy skin

These symptoms are often more noticeable when standing up after sitting or lying down, due to blood pooling in the legs. The heart has to work harder to pump blood against gravity when standing.

Risk Factors for Symptoms

Those more likely to experience symptoms of low blood pressure include:

• Older adults - vascular aging can impair blood pressure regulation
• Teenagers - hormonal changes can affect blood pressure
• Women - hormones and smaller bodies prone to pressure drops
• Endurance athletes - high aerobic capacity expands blood vessels
• People with low BMI - less vascular resistance allows pressure drops
• Pregnancy - circulatory changes and compression of vena cava
• Dehydration - decreased blood volume reduces pressure
• Blood loss or trauma - hypovolemic shock reduces volume

Underlying health conditions, certain medications, and genetics can also lead to chronically low blood pressure. Well explore these factors more in depth next.

What Causes Low Blood Pressure?

There are several possible causes of hypotension, including:

Heart Conditions

Problems with the hearts structure, rhythm, or function can impair its pumping power to create adequate blood pressure:

• Bradycardia - slow heart rate doesnt circulate blood well
• Heart valve problems
• Heart failure
• Heart attack damaging heart muscle
• Dysrhythmias like atrial fibrillation

Endocrine Diseases

Hormonal imbalances and glandular disorders can create low blood pressure:

• Adrenal insufficiency
• Hypothyroidism
• Low aldosterone
• Diabetes - autonomic neuropathy or hypoglycemia
• Pheochromocytoma - tumor causing catecholamine fluctuations

Nervous System Disorders

Neurological conditions disrupting blood pressure regulation mechanisms:

• Autonomic neuropathy
• Parkinson's disease
• Multiple system atrophy
• Amyloidosis - abnormal protein deposits
• Spinal cord injuries or disorders

Autoimmune Disorders

Diseases where the immune system attacks the body can affect blood pressure control:

• Sepsis and septic shock
• Rheumatoid arthritis
• Lupus
• Vasculitis - inflammation of blood vessels
• Sjogren's syndrome

Dehydration

Fluid loss from sweating, vomiting, diarrhea or burns can decrease blood volume and pressure. Electrolyte imbalances may also play a role.

Pregnancy

Hormonal changes and compression of major blood vessels from the womb can lower blood pressure, especially in the first and third trimesters.

Medications

Many prescription and over-the-counter drugs can cause blood pressure drops:

• Diuretics
• Beta blockers
• ACE inhibitors
• Alpha blockers
• Calcium channel blockers
• Alcohol and anesthetics
• Opioids and cannabis
• Antidepressants
• Parkinson's medications
• Erectile dysfunction drugs

Sepsis

A severe infection and inflammatory response can result in dangerously low blood pressure called septic shock.

Neurally Mediated Hypotension

A miscommunication between the heart and brain can cause an inappropriate dilation of blood vessels, pool blood in the legs, and lower pressures.

Genetics

Some chronic cases of low blood pressure may have a hereditary component. Autonomic disorders can be passed genetically.

Risk Factors for Low Blood Pressure

While anyone can develop low blood pressure, certain factors place you at higher risk:

• Being very fit or underweight
• Older age
• Female gender
• Pregnancy
• Endocrine disorders
• Parkinson's disease
• Heart conditions
• history of fainting
• Certain genetic disorders
• Autoimmune diseases
• Spinal cord injury
• Alcohol abuse
• Dehydration
• Sepsis
• Taking certain prescription medications

Those with the above risk factors should have periodic blood pressure monitoring and discuss any concerns with their doctor.

Dangers and Complications of Low Blood Pressure

While most cases of low blood pressure are benign, significant or prolonged drops in pressure can create dangerous complications:

• Fainting - Loss of consciousness from inadequate blood to the brain
• Falls - Dizziness and weakness leading to injuries from falls
• Blurred vision - Reduced ocular perfusion can impair vision
• Poor organ function - Organs receive insufficient blood flow and oxygen
• Shock - Without urgent treatment, shock can lead to organ failure and death
• Heart damage - The heart muscle doesn't receive enough oxygenated blood
• Stroke - Blood supply to parts of the brain is disrupted

Those with symptoms of hypotension after standing, known as orthostatic or postural hypotension, are at higher risk of complications like fainting and falls. The elderly are especially susceptible to dangerous drops in blood pressure from standing up.

When to See a Doctor

Consult a physician promptly if you experience:

• Frequent spells of lightheadedness, blurry vision, or fainting
• Fatigue, lethargy, or weakness interfering with daily life
• Blood pressure under 90/60 mmHg on multiple readings
• Progressively worsening hypotension symptoms
• Postural blood pressure drops greater than 20 mmHg

Seek emergency care for fainting, chest pain, severe headache, shortness of breath, racing pulse, fever, or confusion - which can indicate heart attack, sepsis, shock, or stroke.

Diagnosing Low Blood Pressure

Doctors use a combination of approaches to diagnose hypotension, including:

• Medical history - Recording any symptoms, family history, medications, and existing conditions
• Physical exam - Checking for signs of illness and listening to heart and lungs
• Orthostatic vital signs - Measuring blood pressure lying down, sitting, and standing
• Blood tests - Checking counts, electrolytes, proteins, hormones, and markers of infection or inflammation
• Electrocardiogram (ECG) - Recording the heart's electrical activity
• Echocardiogram - Using ultrasound to examine the heart's structure and function
• Tilt table testing - Monitoring how blood pressure responds to postural changes in a controlled setting
• Autonomic reflex screening - Assessing responses of the autonomic nervous system
• CT or MRI scans - Creating images to check for organ damage or neurological causes

Based on the results, doctors can determine if any underlying conditions are causing the low blood pressure and develop an appropriate treatment plan.

Treatments for Low Blood Pressure

Treatment depends on the severity of symptoms and underlying cause. Options may include:

Increasing Fluid and Salt Intake

Consuming more fluids and sodium can improve blood volume. Electrolyte drinks are ideal.

Compression Stockings

Gradient compression stockings prevent blood from pooling in the legs when standing.

Medications

Drugs that may be prescribed include:

• Fludrocortisone to increase blood volume
• Midodrine to constrict blood vessels
• Beta blockers or antiarrhythmics for heart issues
• Vasopressors for acute pressure drops

Treat Underlying Conditions

Doctors will address any heart disease, hormonal disorders, infections, medications or other underlying problem causing hypotension.

Increase Physical Activity

Regular exercise can help improve blood pressure regulation.

Avoid Triggers

Preventing sharp drops in blood pressure can minimize symptoms, such as avoiding suddenly standing up.

Surgery

Some heart conditions or nervous system disorders may require surgery to correct.

Home Remedies and Lifestyle Changes

Natural ways to boost your blood pressure include:

• Drink 2-3 liters of electrolyte-rich fluids daily
• Increase salt intake
• Wear compressions stockings
• Sleep with head elevated on 2-3 pillows
• Take breaks between position changes
• Exercise regularly to improve cardiovascular fitness
• Raise legs periodically when sitting
• Avoid drugs and alcohol that lower pressure
• Prevent and treat dehydration
• Consume caffeine in moderation
• Keep indoor temperatures comfortably warm

Implementing healthy lifestyle habits like a nutritious diet, stress management, and restorative sleep can also provide benefits.

Living with Low Blood Pressure

Most people can successfully manage mild chronic hypotension with a few adaptations and lifestyle measures. Recommendations include:

• Monitor for lightheadedness and stay well hydrated
• Increase salt and fluid intake before exertion in heat
• Rise slowly and pause before walking after long periods sitting
• Shift positions carefully to avoid dizzy spells
• Exercise regularly to improve pressure regulation
• Wear compression garments to prevent blood pooling
• Use chair exercises to reduce deconditioning
• Be cautious driving or operating machinery
• Implement fall precautions like grip bars in showers
• Carry identification about hypotension condition
• Seek medical care for any severe or worsening symptoms

With proper management, most people with chronic low blood pressure can enjoy regular activities without much disruption or danger.

Outlook for Low Blood Pressure

Hypotension prognosis depends greatly on the underlying cause and severity. Mild chronic cases usually have an excellent long-term outlook with lifestyle changes. Acute drops in pressure from shock, trauma, or medication effects often resolve after treating the root problem.

More severe chronic hypotension related to heart failure, autonomic disorders, or nervous system conditions may have a poorer prognosis. However, even these types can often be well managed with a combination of medications, therapy, and lifestyle modifications.

In general, low blood pressure alone in otherwise healthy people is not considered life-threatening when addressed appropriately. However, the development of concerning symptoms warrants medical evaluation to identify and properly treat any underlying problem.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.