Why is my heart racing?
Not a diagnosis: a head start. These are the three drivers most worth checking first, based on what the evidence says gets missed most often.
Usually benign, always check
Most are ectopic beats amplified by caffeine, stress and poor sleep. New, frequent or with fainting: see a GP.
The stimulant audit
Caffeine, nicotine, decongestants, pre-workout. Count them honestly.
Thyroid, iron, magnesium
The classic testable trio behind a jumpy heart.
TSH, ferritin, U&E + magnesium; ECG via GP if frequent
1. Start a two-minute note so the pattern becomes visible.
2. Take the test list above with you so you can explain the pattern clearly.
3. Read the evidence: Browse the library.
Education, not diagnosis, and never a replacement for your GP or pharmacist. Reference ranges and guidance vary; sudden, severe or worsening symptoms need 111, or 999 in an emergency. By Hussain Sharifi · independent, affiliate-free health research.