Why Is My Blood Pressure Low? Causes, Symptoms, and Treatments

Have you ever felt lightheaded or dizzy when standing up too quickly? Or perhaps you've noticed that your blood pressure readings are lower than normal. If so, you may be wondering - why is my blood pressure low?

In this comprehensive guide, we'll explore the causes, symptoms, dangers, and potential treatments for low blood pressure, also known as hypotension. Read on to learn more about maintaining healthy blood pressure levels.

What is Considered Low Blood Pressure?

Blood pressure is the force of blood pushing against the walls of arteries as blood circulates throughout the body. It is measured in two numbers - systolic pressure (top number) is the pressure as the heart beats and pumps blood, while diastolic pressure (bottom number) is the pressure as the heart relaxes between beats.

Normal blood pressure ranges are:

  • Normal: Less than 120/80 mmHg
  • Elevated: 120-129/Less than 80 mmHg
  • Stage 1 High Blood Pressure: 130-139/80-89 mmHg
  • Stage 2 High Blood Pressure: 140/90 mmHg or higher (Hypertension)

Low blood pressure, or hypotension, is generally defined as:

  • Systolic (top number): Less than 90 mmHg
  • Diastolic (bottom number): Less than 60 mmHg

However, what is considered low can vary depending on your typical blood pressure reading, medications, age, and other factors. Even levels above 90/60 mmHg may cause symptoms in some people. Your doctor can best interpret if your blood pressure is at a healthy level.

Common Causes of Low Blood Pressure

There are many potential causes of low blood pressure, ranging from temporary situations to serious medical conditions. Here are some of the most common reasons for hypotension:


One of the most common reasons people experience low blood pressure is simply not drinking enough fluids. Dehydration causes blood volume to drop, which decreases pressure on artery walls.

Dehydration can occur due to:

  • Insufficient fluid intake
  • Intense exercise, sweating
  • Hot weather and heat exhaustion
  • Illnesses causing vomiting, diarrhea
  • Certain medications like diuretics

Drinking more water and electrolyte drinks can often resolve dehydration-related hypotension.


A variety of prescription medications can lead to low blood pressure, especially in older adults. These include:

  • Blood pressure medications¬†like diuretics, beta-blockers, ACE inhibitors, ARBs, and calcium channel blockers.
  • Antidepressants¬†such as MAOIs and TCAs.
  • Nitrates¬†used for heart disease.
  • Erectile dysfunction drugs¬†like sildenafil.
  • Parkinson's disease medications.
  • Sedatives and anesthetics.

If you take any medications, read the label carefully and be aware they may cause dips in blood pressure. Check with your doctor about dosage adjustments if needed. Never stop a medication without medical supervision.

Prolonged Bed Rest

Being immobile in bed for an extended period can also lead to lower blood pressure. Lack of movement causes blood to pool in the legs rather than circulating normally.

Causes of prolonged bed rest include:

  • Recovery after surgery or childbirth
  • Hospitalization for illness
  • Strict bed rest ordered by a doctor

Getting up and gently moving around, with assistance if needed, can help resolve low blood pressure from bed rest. Compression stockings may also help.

Stress, Fear, or Pain

Experiencing a stressful situation, intense fear, anxiety, trauma, or severe pain can all stimulate the nervous system in ways that lower blood pressure.

Examples include:

  • Receiving upsetting, shocking news
  • Public speaking or performance anxiety
  • Phobias such as fear of heights or flying
  • Abuse, assault, or other distressing events
  • Labor contractions or pain from an injury

While stress-related hypotension is often temporary, chronic stress can cause pressure to drop. Relaxation techniques, therapy, and stress management may help.


Pregnancy often lowers blood pressure, especially in the first 24 weeks. Hormonal changes cause blood vessels to dilate, lowering resistance. Many pregnant women experience dips in blood pressure without negative effects.

However, significant drops can still cause pregnancy-related hypotension symptoms. Lying on the left side, hydration, and compression stockings can help alleviate issues. Notify your OB-GYN if problems persist.

Heart Problems

Some heart conditions reduce the heart's effectiveness at pumping blood, which diminishes pressure:

  • Heart failure¬†- the heart cannot pump adequate blood.
  • Heart attack¬†- blood flow is abruptly blocked to part of the heart.
  • Abnormal heart rhythms¬†like bradycardia, heart block, or atrial fibrillation.

Treating the underlying heart problem is key, which may include medications, surgery, or implanted devices. Call 911 immediately with heart-related chest pain.

Endocrine Disorders

Hormonal disorders of the endocrine system impact blood pressure regulation:

  • Thyroid disorders¬†like hypothyroidism or hyperthyroidism
  • Adrenal insufficiency¬†(Addison's disease)
  • Low blood sugar¬†(hypoglycemia)
  • Pituitary disorders

Replacement hormones, medications, supplements, diet changes, or treatment of the condition itself often resolves associated hypotension.

Blood Loss

Bleeding from major trauma, surgery, gastrointestinal issues, or women's menstrual periods can substantially lower blood volume and pressure.

Seek immediate emergency care for:

  • Significant bleeding from injuries
  • Vomiting or coughing up blood
  • Bloody/black tarry stools
  • Heavy menstrual bleeding

Intravenous fluids, blood transfusions, iron supplements, cauterizing, medications, or surgery may be used based on the cause.

Serious Conditions

Some potentially life-threatening conditions like heart attacks, pulmonary embolisms, sepsis, or allergic reactions can drastically lower blood pressure.

  • Heart attacks¬†- Blood flow is blocked from a section of the heart.
  • Pulmonary embolism¬†- An artery in the lungs is blocked, usually by a blood clot.
  • Anaphylaxis¬†- A whole-body allergic reaction causing blood vessels to dilate severely.
  • Sepsis¬†- The body's response to a severe infection triggers widespread inflammation and blood vessel dilation, crashing blood pressure.
  • Hemorrhagic stroke¬†- Ruptured blood vessels bleed into the brain.
  • Septic shock¬†- A dangerous drop in blood pressure and blood flow from sepsis.
  • Adrenal crisis¬†- The adrenal glands cannot produce enough cortisol and catecholamines to maintain blood pressure.

These life-threatening conditions require emergency medical treatment. Call 911 or seek immediate care if you experience sudden dizziness, shortness of breath, chest pain, signs of stroke, loss of consciousness, or other concerning symptoms associated with a sudden drop in blood pressure. Swift action can be crucial for survival and preventing permanent organ damage in these scenarios.

Recognizing Symptoms of Low Blood Pressure

The symptoms associated with low blood pressure can vary significantly. Here are some of the most common:

Dizziness or Lightheadedness

One of the hallmarks of low blood pressure is feeling dizzy or lightheaded. This occurs when the brain receives reduced blood flow. Changing positions, such as standing up after sitting or lying down, tends to trigger dizziness.

Fainting (Syncope)

In more severe cases, critically low blood pressure can cause temporary loss of consciousness or fainting. This happens when the brain is deprived of oxygen. Fainting necessitates lying or sitting down immediately to avoid injury.

Fatigue and Weakness

Low blood pressure reduces circulation, which can leave you feeling tired, sluggish, and weak. Essential oxygen and nutrients do not reach tissues as efficiently.

Blurred or Fading Vision

Eyes depend on adequate blood flow. With hypotension, vision may become blurry, spotty, or fade in and out.


The autonomic nervous system helps control digestion and nausea. Disruptions from low blood pressure can trigger nausea, vomiting, and abdominal discomfort.

Headache and Muscle Cramps

Headaches and muscle cramps in the calves, feet, or neck are common when blood pressure drops since muscles do not receive sufficient oxygen.

Heart Palpitations

Lightheadedness and dizziness can cause the heart to beat harder and faster to compensate, leading to noticeable heart palpitations.


As less blood reaches the brain, confusion, difficulty concentrating, and memory problems can occur. This is especially likely in older adults.

Cold, Clammy Skin

Low blood circulation causes skin to become cold, clammy, pale, and sweaty. Fingers or toes may also feel numb or tingly.

Pay attention to symptoms of hypotension, especially if they are new, worsening, or impacting your daily life. Symptoms with exercise often indicate a heart issue. Seek medical advice to determine any underlying cause.

Dangers and Need for Treatment

In many cases, low blood pressure may cause no symptoms or minimal temporary symptoms. Chronic low blood pressure without other signs generally is not dangerous and requires no treatment in otherwise healthy people.

However, low blood pressure becomes concerning and merits medical evaluation if it:

  • Occurs with symptoms like dizziness or fainting
  • Causes signs of shock like rapid heart rate, confusion, sweaty skin
  • Happens repeatedly and severely upon standing (orthostatic hypotension)
  • Occurs with known heart, endocrine, or neurological disorders
  • Worsens existing health conditions
  • Results from dehydration, blood loss, or infection

Sudden, significant drops in blood pressure can be life-threatening emergencies, especially with underlying heart problems, blood loss, or sepsis. Immediate treatment is needed when blood pressure crashes.

Even without an emergency, identifying and addressing the root cause of hypotension is beneficial if it is causing bothersome symptoms that impact daily living.

Long-Term Effects of Low Blood Pressure

The long-term effects of chronically low blood pressure depend greatly on the underlying cause and specifics of each individual case.

In an otherwise healthy person, ongoing low blood pressure with minimal or no symptoms generally does not cause damage or require treatment. However, some potentially concerning long-term effects include:

  • Frequent fainting¬†- Repeatedly losing consciousness from blood pressure drops can cause injury from falls. It may signal a serious underlying disorder.

  • Heart or brain damage¬†- If blood flow to vital organs becomes very low, even temporarily, some degree of cell death and organ damage is possible over time.

  • Kidney problems¬†- Kidneys require strong blood flow. Hypotension may impact their function long-term.

  • Erectile dysfunction¬†- Men may have difficulty getting or maintaining erections due to restricted blood flow.

  • Poor concentration and memory¬†- Reduced oxygen to the brain can worsen cognition, especially in older adults.

Discuss any persistent low blood pressure and associated symptoms with your physician to assess possible impacts. Treating reversible underlying causes can help minimize negative effects.

Tips for Improving Low Blood Pressure

If low blood pressure is causing bothersome symptoms, try these self-care tips while consulting your doctor:

  • Increase fluid and salt intake, unless contraindicated by a condition.
  • Avoid sudden position changes. Move slowly from lying to sitting to standing.
  • Take breaks between position changes.
  • Sleep with head of bed slightly elevated.
  • Take small, frequent meals.
  • Exercise regularly to improve heart efficiency.
  • Raise legs periodically when sitting or lying down.
  • Avoid very hot showers or baths.
  • Use compression garments on arms and legs.
  • Identify and treat causes of stress, fear, or pain.
  • If pregnant, lie on your left side, which improves blood flow.
  • Ensure adequate iron levels.
  • Check for drug interactions with medications.
  • Time high blood pressure medications for when pressure is highest to avoid over-lowering it.
  • Consider natural supplements like vitamin B12, licorice, ginseng, and magnesium. Consult your doctor first.
  • Carry snacks and fluids when out in case pressure drops.
  • Stay safe if you feel dizzy - sit or lie down promptly.
  • Move slowly and grasp handrails when standing up.
  • Know emergency moves if you feel faint - cross legs to tense muscles or lay on floor and elevate legs.

Implementing lifestyle adjustments, taking care with position changes, staying hydrated, and getting any underlying condition treated can help minimize problematic hypotension symptoms.