Supine Hypotension: What to Know

Blood pressure changes with posture, activity, meals, fluid balance, and medicines. A low reading while lying down is interpreted alongside your usual readings and symptoms. Some people have no symptoms, while others notice tiredness, blurred vision, nausea, unsteadiness, or a faint feeling. Dehydration, blood loss, infection, heart conditions, hormone problems, and medicines can affect pressure. One reading cannot explain the cause, so a clinician may repeat measurements and compare lying and standing readings.

Move slowly when changing position and sit before standing. Keep water nearby if a clinician has said normal fluid intake is suitable for you. Avoid alcohol and overheating if they trigger symptoms, and use support when walking during an episode. Do not increase salt or alter prescribed treatment without advice, particularly if you have heart or kidney disease. A [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/) can help review medicines, symptoms, and blood-pressure records.

Get urgent help for fainting with an injury, chest pain, severe breathing difficulty, confusion, new one-sided weakness, or difficulty speaking. Seek prompt review if low readings recur, you fall, symptoms interfere with eating or walking, or the change follows vomiting, diarrhoea, bleeding, or a medicine change. If you feel dizzy but have no emergency symptoms, sit or lie safely and arrange medical advice. See [Dizziness](/symptoms/dizziness/) for related symptom guidance.

What blood-pressure readings should I record, and in which positions? Could my medicines, fluid intake, or another illness explain the pattern? Is it safe for me to increase fluids or salt? How can I reduce my risk of falling?