Cardiovascular · Cor
Heart
It has beaten every second of your life without once being told to.
- Mass
- 250 to 350 g
- Output at rest
- ~5 L / min
- Beats in a lifetime
- ~2.5 billion
- Own blood supply
- Coronary arteries, ~5% of output
What it does
A four-chambered pump that moves roughly five litres of blood every minute at rest, sending it to the lungs for oxygen and then out to every cell you own. The whole circuit takes under a minute.
The marvel
Your heart generates its own electricity. A cluster of cells called the sinoatrial node fires on its own rhythm, which is why a heart removed from the body and kept alive keeps beating with nothing attached to it. Your brain can suggest a rate. It cannot issue the beat.
How to serve it well
Move at a conversational pace
Around 150 minutes a week of moderate activity is the most consistently supported intervention in cardiovascular medicine. Intensity matters less than doing it at all.
Know your blood pressure
High blood pressure has no symptoms until it has already done damage. It is the cheapest number to measure and one of the most predictive you will ever get.
Protect your sleep
Habitually sleeping under six hours is associated with higher cardiovascular risk independently of diet and exercise.
Treat smoking as the emergency it is
Quitting produces measurable cardiovascular risk reduction within the first year, and the benefit continues for decades.
Book an appointment
- Breathlessness doing things that used to be easy
- Ankles or legs that swell by the end of the day
- Palpitations that recur, or a pulse that feels irregular at rest
- Chest discomfort that reliably appears with exertion and eases with rest
Emergency, go now
- Chest pressure, tightness, or heaviness lasting more than a few minutes
- Pain spreading to the jaw, neck, back, or either arm
- Chest discomfort with sweating, nausea, or lightheadedness
- Sudden severe breathlessness, especially lying flat
What you may have been told
“Supplements can "unclog" your arteries.”
Nothing sold over the counter reverses atherosclerotic plaque. The interventions with real evidence are unglamorous: blood pressure control, lipid management where indicated, not smoking, and movement.
Where this comes from
- World Health Organization · Physical activity fact sheet
- American Heart Association · Heart attack warning signs
- NHS · Cardiovascular disease
LUMEN is education, not medical advice, and it cannot know anything about you. It does not diagnose. If something here matches what you are experiencing, take it to a clinician who can examine you.