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

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.