Every January the same advice comes round: join a gym, drink more water, try a detox, get your 10,000 steps. Some of it is sensible and most of it is generic. None of it tells you anything about you: whether your iron stores are running low, whether your blood sugar has been creeping up, or whether the tiredness you have put down to winter has a measurable cause.
A blood test does. Not everything, and not on its own, but it gives you a baseline: a set of real numbers to set goals against and to compare with next year. This guide covers what is actually worth testing at the start of the year, what a blood test cannot tell you, and how to choose a panel without paying for markers you do not need. At WMG Health, our private blood testing clinic at 134 Harley Street, London, every result is reviewed by a GMC-registered doctor and no GP referral is needed.
Why a baseline beats a resolution
Most resolutions fail for a simple reason: they are not tied to anything you can measure. “Get healthier” is hard to track. “Get my ferritin back above 30” or “bring my HbA1c back under 42” is not.
Several of the most common, fixable problems in UK adults are also the quietest:
- Low iron stores can drag your energy down for months before anaemia appears on a basic blood count. See what low ferritin feels like.
- Low vitamin D is common in the UK through winter: levels typically decline from October and are lowest around February. Our guide to vitamin D deficiency symptoms explains why.
- Raised blood sugar in the pre-diabetes range usually causes no symptoms at all. Our guide to what your HbA1c means covers the numbers.
- An underactive thyroid develops slowly and is easy to mistake for tiredness, weight gain and feeling the cold. See our guide to thyroid blood tests.
None of these will be picked up by a new trainer or a juice cleanse. All of them show on a blood test.
What a blood test cannot tell you
A useful health check is honest about its limits. A blood panel does not measure:
- Blood pressure, which is one of the most important numbers for long-term heart and stroke risk. Many pharmacies offer a blood pressure check, and it takes minutes.
- Fitness, strength or sleep quality.
- Mental health. If your mood has been low for weeks, speak to your GP.
- Cancer. A routine wellness panel is not a cancer screen. Keep attending NHS screening (cervical, breast and bowel) when you are invited.
If you are aged 40 to 74 in England and do not have certain existing conditions, you are also eligible for a free NHS Health Check every five years, which checks your blood pressure and cholesterol and estimates your risk of heart disease, stroke, type 2 diabetes and kidney disease. Private testing works well alongside it: a broader set of markers, on your timetable.
The core: what most people should start with
For most adults without a specific concern, the General Wellness panel (£279) is the fixed-price starting point. It covers:
| Marker | Why it matters at the start of the year |
|---|---|
| Full blood count (FBC) | Anaemia, infection and platelets; the backbone of any blood check |
| Iron studies, including ferritin | Iron stores and how well you are using them; low stores are a common, fixable cause of tiredness |
| Vitamin D | Deficiency is common through the UK winter |
| Vitamin B12 | Energy, nerves and red blood cells; more likely to be low on a vegan diet without supplements, and with some long-term medicines such as metformin and proton pump inhibitors |
| Folate | Works with B12 in red blood cell production; more likely to be low with an unbalanced diet or heavy drinking, and needed in higher amounts in pregnancy |
| Thyroid function | An under- or overactive thyroid is a classic, treatable cause of low energy and weight change |
| CRP and ESR | Markers of inflammation |
| Zinc | Immunity, hormones and tissue repair |
| Liver function tests, including ALT | Particularly useful if you regularly drink above 14 units a week, carry extra weight, or take long-term medicines that affect the liver |
| Kidney function (urea, creatinine, sodium, potassium) | Particularly relevant if you have high blood pressure or diabetes |
| Lipid profile (cholesterol) | A heart-risk baseline, especially if you are over 40, have a family history of early heart disease, or are about to change your diet or training |
| HbA1c | Average blood sugar over two to three months; NICE recommends a type 2 diabetes risk assessment for adults from 40, from 25 for some ethnic groups, and for people with conditions such as obesity, high blood pressure or PCOS |
Fast for at least 12 hours beforehand, but not much longer than 12 hours. Water is fine, and encouraged, but no food or other drinks, and do not stop prescribed medication. A morning appointment between 8am and 10am is preferred. Avoid alcohol for 24 to 48 hours and strenuous exercise for 48 hours beforehand, and avoid a large cooked-meat meal in the few hours before. Do not take iron tablets for 24 hours or a B12 supplement beforehand, and if you take thyroid tablets, take them after the draw. If you take folate, B-complex or multivitamin supplements, hold them for 24 to 72 hours before your test, because recent supplementation can hide a real deficiency.
A note on cholesterol: NICE does not assess heart risk from cholesterol alone. NICE guideline NG238 recommends the QRISK3 tool to estimate your 10-year risk of cardiovascular disease for people aged 25 to 84, using several risk factors recorded in your medical record. That is why a cholesterol check is most useful when someone also knows your blood pressure and history.
Add-ons worth knowing about
A few markers sit outside the fixed panels, and whether they are worth adding depends on your history. Fasting glucose and fasting insulin, for example, can help when HbA1c may be unreliable or insulin resistance is suspected, and both need an overnight fast. A clinician can add these through a custom panel, with the price confirmed in writing before you book.
When a different panel makes more sense
If you already have a specific concern, start there rather than with a general screen:
- Tired, low libido, mood changes or hair changes: the Hormone Specialist panel (£299) covers DHT and the wider androgen panel, total testosterone, SHBG, LH, FSH, prolactin, oestradiol, thyroid function, zinc and CRP.
- Men with possible low testosterone: the Testosterone Panel (£199) measures total and free testosterone, SHBG, LH, FSH and DHT, drawn between 8am and 10:30am, with fasting for 8 to 12 hours preferred but not essential. See low testosterone symptoms in men.
- Women with cycle changes, or in their 40s and wondering about perimenopause: the Female Hormone Panel (£329) covers FSH, LH, oestradiol, progesterone, prolactin, SHBG and total testosterone. Our guide to perimenopause symptoms and when a blood test helps explains when testing is and is not useful.
- Hair shedding or thinning: the Hair Loss Essentials panel (£249) covers iron studies, vitamin D, B12, folate, thyroid function (TSH, FT3 and FT4), a full blood count, zinc and CRP.
If your main complaint is feeling exhausted, our guide to always being tired no matter how much you sleep walks through the causes and tests in more detail.
If your resolution is to get fitter
A new training plan is one of the best reasons to get a baseline, and it is one of the things the General Wellness panel is designed for. Two markers are worth particular attention:
- Ferritin. The British Society of Gastroenterology notes that iron deficiency is common in endurance athletes. If you are about to start a big training block, knowing your ferritin first means a low result can be looked into with your GP rather than guessed at.
- Vitamin D. Relevant to bone and muscle health, and levels are typically lowest in late winter, just as many people start a January plan.
A repeat test after you have made changes can show whether they are working, and gives you something more meaningful than the bathroom scales to track. How soon to repeat depends on the marker, and the reviewing clinician can advise.
Three things not to do
- Do not buy the biggest panel you can find. More markers means more borderline results, and more borderline results means more worry and more follow-up tests. Test with a question in mind.
- Do not start a stack of supplements the week before your test. You will measure the supplements, not your baseline.
- Do not treat a normal result as a licence. A clean panel is good news, but it does not cancel out smoking, heavy drinking or high blood pressure.
Timing your test
- After a heavy festive period, give it a few weeks if you want your liver markers to reflect your usual habits rather than December. Our guides to Dry January and your liver and what your body needs after Christmas explain why.
- If you have had a cold or flu recently, inflammation markers can be temporarily raised, and ferritin, which rises with inflammation, can look normal when your iron stores are actually low. Waiting until you have fully recovered gives a cleaner baseline.
- Book a morning appointment if hormones are part of your panel, and follow any fasting instructions for your specific tests.
Getting tested at WMG Health
Book the General Wellness panel (£279) as your baseline, or ask us to build a custom panel around your age, history and goals. Every result is reviewed by a GMC-registered doctor with written commentary. Results are released as each marker is reviewed, and we confirm the expected timeframe when you book. If anything needs follow-up, we will explain it and recommend sharing the results with your GP.
Common questions
Is an annual blood test worth it if I feel fine? It depends on what you want from it. There is no NHS programme of routine blood tests for healthy adults beyond the NHS Health Check. A private baseline can be useful if you want numbers to track, or if you have risk factors or vague symptoms, but a normal result is not a guarantee, and extra markers can throw up borderline results that need follow-up.
Does the General Wellness panel include cholesterol or blood sugar? Yes. As well as a full blood count, iron studies, vitamin D, B12 and folate, thyroid function, CRP and ESR, and zinc, it includes a lipid profile (cholesterol), HbA1c, and liver and kidney function.
Do I need to fast? Yes. The General Wellness panel needs a fast of at least 12 hours, with water only, but not much longer than 12 hours. Some add-ons, such as fasting glucose or fasting insulin, also need an overnight fast, and we will tell you when you book.
How often should I repeat it? There is no fixed rule. Many people repeat a general baseline every year or two, and sooner if a result needs follow-up or you are making a specific change. The reviewing clinician can advise on timing for your results.
Is this a replacement for the NHS Health Check? No. The NHS Health Check includes blood pressure and a cardiovascular risk assessment, and it is free. A private panel adds markers the Health Check does not cover and lets you test on your own timetable.
Related reading
- How Often Should You Have a Health Check?: age-by-age guidance on health checks and blood tests.
- Private Blood Test Cost in London: Price Guide: what each panel costs and what drives the price.
- NHS or Private Blood Test? How to Choose: when an NHS test is the right first step and when a private test makes sense.
- High Cholesterol Result: What Happens Next: what happens after a raised cholesterol result.
- Blood Test Normal Ranges UK: A to Z: typical ranges for every marker we cover, with links to each marker page.
Sources
- NHS: NHS Health Check; Vitamin B12 or folate deficiency anaemia; Calculating alcohol units; Vitamin D. nhs.uk
- NICE Guideline NG238: Cardiovascular disease: risk assessment and reduction, including lipid modification. nice.org.uk
- NICE Public Health Guideline PH38: Type 2 diabetes: prevention in people at high risk. nice.org.uk
- British Society of Gastroenterology: Guidelines for the management of iron deficiency anaemia in adults (Snook et al, Gut 2021). bsg.org.uk
- Scientific Advisory Committee on Nutrition (SACN): Vitamin D and health (2016). gov.uk
This article is for general information only and does not constitute clinical advice. If you have concerns about your health, book an appointment or speak to your GP.