What Is Low Blood Pressure? Causes, Symptoms and When to See a Doctor

Dr. S. Muthukkumaran

Cardiothoracic & Vascular Surgery · Iswarya Hospital

Low blood pressure (hypotension) can cause dizziness, fainting, and fatigue. Learn what causes it, when it's dangerous, and how to manage it effectively.

Blood pressure below 90/60 mmHg is generally considered low blood pressure (hypotension). While high blood pressure gets more attention, low blood pressure can also cause significant symptoms and, in severe cases, be life-threatening.

What Is Normal Blood Pressure?

| Category | Systolic (upper) | Diastolic (lower) |

|----------|-----------------|-------------------|

| Normal | 90–120 mmHg | 60–80 mmHg |

| Low (hypotension) | Below 90 mmHg | Below 60 mmHg |

| High (hypertension) | Above 130 mmHg | Above 80 mmHg |

Symptoms of Low Blood Pressure

Dizziness or lightheadedness, especially when standing up

Fainting (syncope)

Blurred vision

Fatigue and weakness

Nausea

Lack of concentration

Rapid, shallow breathing

Cold, pale, or clammy skin

Types of Hypotension

1. Orthostatic hypotension — BP drops when you stand up quickly (postural hypotension)

2. Postprandial hypotension — BP drops after eating (common in elderly)

3. Neurally mediated hypotension — occurs after prolonged standing, more common in young people

4. Severe hypotension (shock) — a medical emergency caused by infection, bleeding, or heart failure

Common Causes

Dehydration — most common cause

Anaemia (low haemoglobin)

Blood loss (internal or external)

Heart problems (low heart rate, heart failure)

Endocrine disorders (hypothyroidism, Addison's disease)

Medications — diuretics, antihypertensives, antidepressants

Prolonged bed rest

Pregnancy (BP is normally slightly lower in pregnancy)

Severe infections (sepsis)

When Is Low BP Dangerous?

Low BP becomes an emergency when accompanied by:

Chest pain or shortness of breath

Confusion or loss of consciousness

Fever above 38.5°C (may indicate septic shock)

Heavy bleeding

Signs of stroke (facial droop, arm weakness, speech difficulty)

Managing Low Blood Pressure

For mild hypotension:

Increase fluid and salt intake (if not contraindicated)

Eat smaller, more frequent meals

Avoid alcohol

Rise slowly from sitting or lying positions

Wear compression stockings

Avoid prolonged standing in hot weather

For chronic or severe cases, medical evaluation is essential to identify the underlying cause.

Iswarya Hospital's Cardiology and Internal Medicine teams provide thorough evaluation and management of blood pressure disorders.

Tags:

#low blood pressure#hypotension#cardiology#dizziness#fainting

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