Beta Blocker
A medicine that slows the heart rate and blunts the effects of adrenaline.
What it means
Beta blockers block beta-adrenergic receptors, reducing the effect of adrenaline on the heart and blood vessels. The heart slows, contracts less forcefully, and blood pressure falls.
Uses extend well beyond the heart:
- Angina, heart failure and after a heart attack
- Atrial fibrillation, to control rate
- Migraine prevention
- Physical symptoms of anxiety — tremor, palpitations, sweating
- Essential tremor
- Overactive thyroid, for symptom control
In practice
Cardioselective beta blockers such as bisoprolol act mainly on the heart; propranolol is non-selective and crosses into the brain, which is why it works for migraine and tremor.
They blunt the warning symptoms of low blood sugar in diabetes, which needs care.
Why it matters
Beta blockers must never be stopped abruptly after regular use — rebound rapid heart rate, raised blood pressure and, in heart disease, angina or heart attack can follow. They are tapered down.
For anxiety, a beta blocker treats the physical symptoms only. It does nothing for the underlying worry, and is best used alongside psychological treatment rather than instead of it. Caution is needed in asthma.
Clinically reviewed by Dr Mohammad Zubair Khan, GMC 7563469
Last reviewed
August 30, 2026