Understanding Your Heart Health Metrics

Your blood pressure read a little high at the pharmacy, or a work health check flagged your cholesterol. Now you want to know what the numbers actually mean.

Blood pressure, cholesterol and a resting ECG each do a different job, and none of them is a diagnosis on its own. Understanding what each one measures is the first step towards preventing heart disease, which remains a major health concern.

If you'd like all three checked and explained by a doctor, the Essential Health MOT at 117a Harley Street covers them in one visit for £495.

Blood pressure: what the numbers mean

High blood pressure (hypertension) often has no symptoms, but over time it can damage your arteries, heart, kidneys and brain. A reading of 120/80 mmHg is generally considered normal. The top number (systolic) is the pressure when your heart beats, and the bottom number (diastolic) is the pressure between beats.

The NHS says you're usually considered to have high blood pressure if a healthcare professional measures 140/90 or higher. At home, the threshold is 135/85 or higher. One raised reading isn't a diagnosis. Nerves, caffeine and a rushed arrival can all push it up, so a raised result is repeated. NICE recommends confirming it with home or 24-hour ambulatory monitoring.

Cholesterol: good and bad

Cholesterol is a fatty substance in your blood. LDL (low-density lipoprotein) is often called 'bad' cholesterol because it can build up in artery walls. HDL (high-density lipoprotein) is 'good' cholesterol because it helps remove LDL from your bloodstream.

The NHS gives healthy levels as total cholesterol below 5mmol/L, non-HDL cholesterol below 4mmol/L, and HDL above 1.0mmol/L for men or above 1.2mmol/L for women. A doctor reads these numbers alongside your age, blood pressure, smoking, diabetes and family history. It's your overall cardiovascular risk, rather than any one figure, that decides what happens next.

ECG: what a resting heart trace shows

A resting electrocardiogram (ECG) records your heart's electrical activity for a short time while you lie still. It can show rhythm problems such as atrial fibrillation, and signs that point to past heart damage or a thickened heart muscle. A normal resting ECG can't rule out narrowed coronary arteries, so it's one part of the picture rather than an all-clear.

Regular exercise, a balanced diet and managing stress all help keep these numbers healthy. If yours are out of range, medication and lifestyle changes can help bring them back under control.

Screening or a specialist review?

If you feel well and want a baseline, a screening check is the right place to start. The Essential Health MOT at The Health Screening Clinic, 117a Harley Street, is £495. It includes a doctor's physical examination, an ECG, a full lipid profile, glucose and HbA1c, with an in-person review of your results.

Book a specialist review if your readings stay high on repeat checks or a result has already been flagged. The same goes for any heart concern that needs a specialist. For that, see the cardiology consultation with Prof Darrel Francis at Medical Express Clinic.

When to call 999

Call 999 for chest pain or pressure, especially if it spreads to your arm, jaw, neck or back, or comes with breathlessness, sweating or feeling sick. Call 999 too for sudden weakness of the face or arm, or difficulty speaking.

Sources

• NHS. High blood pressure
• NHS. Cholesterol levels
• NICE. Hypertension in adults: diagnosis and management (NG136)
• NHS. Electrocardiogram (ECG)
• NHS. Heart attack

Written By

Stephen Lingam

Managing Director

Managing Director of Medical Express Clinic and the Health Screening Clinic since 1984. Over 40 years of operational experience in private healthcare on Harley Street, overseeing patient care, clinical standards, and service delivery.

Medically Reviewed

Prof Darrel Francis

MA, MD, FRCP

Consultant Cardiologist

GMC: 4062833

Renowned cardiologist providing expert cardiac oversight for our comprehensive health MOTs.

Last reviewed: 25/09/2026