Private blood testing has become an industry of its own, and the marketing leans heavily on more is better — panels of 40, 60, 80 biomarkers, sold as a full picture of your health. As a GP, I spend a surprising amount of time helping people interpret results from panels they did not need. Here is a more honest guide to choosing.
Start with the question, not the panel
A blood test is only as useful as the question it answers. Tired all the time? That is a specific, well-trodden work-up — full blood count, ferritin, thyroid function, B12 and folate, HbA1c, and a few others depending on your history; we have written a full guide to blood tests for fatigue. Worried about your heart? Cholesterol profile and HbA1c inside a proper cardiovascular risk assessment beats any mega-panel. General reassurance with no specific symptom? A structured Well Person Check covers the markers that actually change management.
The panels most people actually need
- Full blood count — anaemia, infection, some blood disorders. (What an FBC shows.)
- Ferritin — iron stores; low ferritin is one of the commonest findings in tired women. (Ferritin explained.)
- Thyroid function (TSH ± T4) — the great mimic: fatigue, weight change, mood, periods.
- HbA1c — three-month blood sugar average; picks up diabetes and pre-diabetes.
- Lipid profile — cholesterol, interpreted alongside blood pressure and family history, not in isolation.
- Vitamin B12, folate and vitamin D — cheap, common deficiencies, genuinely fixable.
Beyond these, tests earn their place only when your history suggests them — hormonal profiles for period problems, PSA after a proper conversation about its limitations, coeliac screening for gut symptoms.
Why interpretation matters more than the draw
Every large panel produces at least one number slightly outside the reference range, because that is how reference ranges work. Sold without a doctor attached, that flagged line becomes a month of anxiety and a string of Google searches. Any private blood test worth paying for includes a clinician who knows your history reviewing the results with you — and, when something genuinely needs action, arranging it. That is how we run it: bloods are taken on site during a private GP appointment in EC1, results are usually back within days, and you hear from a doctor, not a PDF.
Practicalities
We are at 1-5 Portpool Lane, Central London, four minutes from Chancery Lane, Monday to Saturday. A GP consultation is £100 with same-day availability most days; blood tests are added to the same visit, so there is no second appointment or draw fee. If you already have results from elsewhere and want them properly explained, start with our guide to understanding your blood work — or bring them with you.