Some blood tests can show signs that may need further investigation, such as inflammation, anaemia, abnormal liver markers, or specific tumour markers. However, a standard blood test cannot reliably confirm or rule out cancer on its own.

Cancer diagnosis usually requires further assessment, which may include a GP or specialist review, imaging scans, biopsies, or more specific tests.

For a tiredness blood test, the results may help identify common causes of fatigue such as low iron, low vitamin D, thyroid imbalance, or inflammation, but it is not designed as a cancer screening test.