Which blood tests are worth having when you feel well?
Short answer: a sensible well-person blood test checks a small number of common, treatable things: cholesterol, blood sugar, kidney and liver function, blood counts, iron stores and thyroid function. It cannot screen for everything, and more tests do not always mean better health.
What a sensible baseline usually includes
Cholesterol: a lipid profile helps assess heart disease risk.
Blood sugar: HbA1c can pick up raised blood sugar before symptoms appear.
Kidney and liver function: both can be abnormal without symptoms.
Full blood count and ferritin: look for anaemia and low iron stores.
Thyroid function: an underactive thyroid is common and treatable. See the TSH test.
Ready-made options include the Well Man check, the Advanced Well Woman check and the full health screening.
What blood tests cannot do
A normal blood test does not mean you are free of disease. Blood tests do not screen for most cancers, and they cannot replace NHS screening programmes such as bowel, breast and cervical screening, or the NHS Health Check offered every five years to adults aged 40 to 74 in England.
The downside of testing everything
Every extra test adds a chance of a result that is slightly out of range but harmless. That can cause worry and further unnecessary tests. A focused set chosen for your age, sex, family history and lifestyle is usually better than the longest list.
When a baseline is most useful
You are over 40, or have a family history of heart disease, diabetes or thyroid disease
You want a starting point to compare against future tests
You are starting a new fitness, diet or weight programme
You have not had a check for several years
If you have symptoms
A well-person check is for people without symptoms. If you have new or worrying symptoms, speak to your GP rather than relying on a screening panel.
Frequently asked questions
How often should I have a well-person blood test?
There is no fixed rule. Many people repeat a baseline every one to two years, or sooner if a result was borderline or something in their health changes.
Do I need to fast?
Many profiles include glucose or triglycerides, which are best after fasting. Check the preparation notes for your chosen test.
Is a full body MOT worth it?
It can be, if the tests are chosen sensibly and you understand what they do and do not cover. A clinician can help you decide what to include.
Related reading
Clinically reviewed by Zak Toon, ACP, on 15 October 2026.
This article is general information based on UK guidance from NHS and NICE. It is not personal medical advice. If you are worried about your health or have symptoms, speak to your GP or call 111.
