Understanding Low Blood Pressure (Hypotension)

Blood pressure is an important health indicator that can provide insight into the status of your heart and blood circulation. The pressure comes from blood pushing against the walls of the arteries as the heart pumps blood. When the pressure reading is lower than normal, it is called hypotension or low blood pressure.

Low blood pressure is generally considered to be a systolic (top number) reading of less than 90 mm Hg or a diastolic (bottom number) reading of less than 60 mm Hg. For some people, lower than normal blood pressure does not cause any symptoms or problems. But for others, persistently low blood pressure can lead to dizziness, fainting, fatigue, lack of concentration, blurred vision, nausea, and cold, clammy skin. Severely low blood pressure can deprive your body's organs of oxygen and nutrients, which can lead to life-threatening shock.

Causes of Low Blood Pressure

There are many potential causes of low blood pressure, including:

Heart conditions like bradycardia, heart valve problems, heart attack, and heart failure
Endocrine problems like adrenal insufficiency, hypothyroidism, and low blood sugar (hypoglycemia)
Dehydration from vomiting, diarrhea, sweating, or diabetes
Severe infection (septic shock)
Allergic reaction (anaphylaxis)
Blood loss from major injury or internal bleeding
Pregnancy
Nutritional deficiencies
Medications like diuretics, beta blockers, ACE inhibitors, calcium channel blockers, and vasodilators
Autonomic neuropathy
Neurally mediated hypotension

In some cases, doctors are unable to determine an exact cause for chronic low blood pressure. This is referred to as idiopathic hypotension.

Risk Factors

Certain factors can increase your risk of developing low blood pressure, such as:

Being over the age of 65
Having diabetes, Parkinson's disease, or malnutrition
Taking certain medications, like diuretics and drugs for Parkinson's
Drinking excess alcohol
Having an eating disorder
Being dehydrated
Having adrenal insufficiency
Being pregnant
Having endocrine system disorders
Having severe infections or sepsis

Symptoms of Low Blood Pressure

Some people with low blood pressure experience obvious symptoms, while others have such mild hypotension that they are unaware of it. Common symptoms include:

Dizziness or lightheadedness - This occurs when the brain receives reduced blood flow. Sitting or standing up quickly can trigger it.
Fainting (syncope) - Severely low pressure can cause you to lose consciousness temporarily. It happens when blood flow to the brain drops suddenly.
Lack of concentration - Insufficient blood and oxygen to the brain can make it hard to focus or think clearly.
Blurred vision - Eyes rely on a steady blood supply, so low pressure can cause visual disturbances.
Nausea - The cardiovascular system helps control nausea signals in the brain, so low pressure can trigger nausea.
Fatigue - Lethargy and weakness occur when your body doesn't get enough oxygenated blood.
Cold, clammy skin - Narrowed blood vessels in the skin leave you feeling chilled and damp.
Depression - Low blood pressure affects mood by reducing blood flow to the brain.

When Low Blood Pressure is Concerning

Occasionally experiencing low blood pressure symptoms after standing up too quickly is usually not a major concern. But some situations do warrant medical attention:

Blood pressure drops suddenly and causes fainting.
Symptoms are frequent and interfering with daily life.
You have risk factors like heart disease, diabetes, or Parkinson's.
Readings are very low - under 90/60 mm Hg.
You are pregnant and pressure drops.
Hypotension occurs with a head injury.
It coincides with unexplained chronic fatigue.

Severely low blood pressure can be life-threatening, especially for the elderly and those with heart problems. Seek immediate help if pressure drops severely and you experience chest pain, trouble breathing, change in mental status, or sudden severe headaches - which can indicate shock, heart attack, or stroke.

Low Blood Pressure in the Elderly

Low blood pressure is more concerning for older adults for several reasons:

Blood vessels stiffen with age, making it easier for pressure to drop with position changes.
Elderly people often take medications that can lower pressure, like diuretics.
Conditions like heart failure and Parkinson's occur more often in seniors.
The brain shrinks with age, increasing susceptibility to low pressure.
Falls are more dangerous for the elderly and can be caused by dizziness from hypotension.

Seniors should have their blood pressure checked more frequently and monitor for any symptoms of hypotension. Preventing dehydration, changing positions slowly, compression garments, increased salt, and adjusting medications can help manage low blood pressure.

Low Blood Pressure During Pregnancy

Blood pressure naturally tends to be lower during pregnancy due to hormonal changes and expansion of the circulatory system. But excessively low readings can potentially impact blood flow to the placenta and fetus. Causes include:

Low blood sugar
Dehydration
Heat exhaustion
Heart or endocrine disorders
Large amount of amniotic fluid (polyhydramnios)
Ectopic pregnancy
Miscarriage

Pregnant women should avoid standing for long periods, take frequent breaks, stay hydrated, and move their legs to aid blood flow. They should contact their doctor if pressure drops substantially or they feel dizzy or faint.

Diagnosing Low Blood Pressure

Doctors use several methods to diagnose hypotension:

Review symptoms - The doctor will ask about symptoms of fatigue, dizziness, fainting, nausea, blurred vision, and depression.
Medical history - Your medical history can reveal conditions, like diabetes or Parkinson's, that increase hypotension risk.
Physical exam - An exam helps rule out neurological causes and listen to the heart.
Blood pressure readings - Repeat readings in different positions determine if pressure is abnormally low.
Blood tests - Blood counts, electrolytes, proteins, thyroid, and hormones help uncover medical causes.
Electrocardiogram (ECG) - An ECG checks for heart abnormalities contributing to low pressure.
Tilt table test - This assesses how your pressure responds to position changes.

Normal Blood Pressure Range

Normal blood pressure ranges are:

Normal: Less than 120/80 mm Hg
Elevated: 120-129/Less than 80 mm Hg
Stage 1 Hypertension: 130-139/80-89 mm Hg
Stage 2 Hypertension: 140/90 mm Hg or higher
Hypotension (low): Less than 90/60 mm Hg

But normal ranges can vary based on age, fitness level, medical conditions, and other factors. It's best to discuss your healthy range with your doctor.

Treatment for Low Blood Pressure

Treatment for hypotension depends on the cause and severity of low blood pressure. Options can include:

Treating underlying conditions - Fixing issues like heart disease, diabetes, and hypothyroidism can resolve low pressure.
Adjusting medications - Lowering or changing drugs that reduce pressure, like diuretics and vasodilators, can help.
Increasing fluid and salt intake - More fluids and sodium increase blood volume to raise pressure.
Compression garments - Special stockings or abdominal bands can prevent blood from pooling in legs.
Raising head of bed - Letting gravity help push blood to the brain can alleviate symptoms at night.
Increasing physical activity - Exercise helps prevent deconditioning and pooling of blood.
Avoiding triggers - Preventing rapid position changes, standing too long, heat, and alcohol ingestion can help.
Medications - In severe cases, drugs like fludrocortisone, vasopressors, and inotropes might be used.

Implementing lifestyle changes, treating medical conditions, adjusting prescriptions, and consulting doctors can help manage low blood pressure.

Preventing Low Blood Pressure

You may be able to reduce your risk of developing hypotension by:

Staying hydrated - Drinking enough fluids prevents dehydration and blood volume depletion.
Increasing salt intake - Getting enough sodium helps maintain fluid balance.
Avoiding excess alcohol - Large amounts of alcohol can dilate blood vessels.
Wearing compression garments - Compression stockings prevent blood pooling in legs.
Raising head of bed - Letting gravity help blood flow to the brain can prevent nighttime hypotension.
Exercising regularly - Physical activity strengthens the heart and blood vessels.
Taking breaks when standing - Avoid prolonged standing and sit or lay down if you feel lightheaded.
Changing positions slowly - Rise gradually from lying to sitting to standing to avoid pressure drops.
Maintaining a healthy weight - Obesity strains the cardiovascular system.
Eating balanced diet - Proper nutrition prevents deficiencies impacting blood pressure.

Making lifestyle modifications can lower your chances of significant drops in blood pressure.

Outlook for Low Blood Pressure

The prognosis for low blood pressure depends on the underlying cause and how low readings drop. Mild chronic hypotension can often be managed with lifestyle measures and rarely shortens life span. But severely low pressure can be life-threatening.

Acute drops in blood pressure that deprive the brain and heart of oxygen can lead to organ damage, shock, heart attack, stroke, and sudden death. Extremely low pressure must be treated immediately with IV fluids and medications.

Elderly adults with frequent dizziness, fainting, and very low pressure measurements generally face a poorer prognosis. Hypotension increases their risk of dangerous falls and makes underlying medical conditions harder to treat.

Pregnant women with sustained blood pressure drops can potentially have complications with low birth weight, preterm delivery, and stillbirth. Tight blood pressure control is necessary for the health of both mother and baby.

People with conditions like diabetes, Parkinson's, and sepsis who develop hypotension typically face more complications in managing their disease. But overall, with proper treatment and lifestyle changes, many people with mild to moderate low blood pressure can live normal healthy lives.

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.