Tired all the time? 18 blood tests to have
Alot of people have unexplained tiredness. Doctors sometimes call this TATT, tired all the time.
After a full history and examination, we recommend the following tests. The syndrome should be taken seriously and investigated properly.
So. What are the 18 common blood tests, and what do they check for?
Note. Some of these are groups if blood tests.
Haematology
1. Full blood count – to assess for anaemia, polycythaemia, haematological malignancy
2. Ferritin, B12 and folate – for iron, B12 and folate deficiency; that can cause anaemia
3. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) — may be raised in chronic infection, inflammation, autoimmune disease and neoplasia. These are good ‘trouble at mill’ tests; if normal, less likely to be anything serious
Note. Strangely, CRP can be low in active SLE (lupus).
Biochemistry
5. Urea and electrolytes, eGFR and CK — to assess for chronic kidney disease (CKD) and/or electrolyte imbalance; CK for muscle disorders
6. Liver function tests (LFTs, now called liver enzymes) — to assess for liver disease
7. Bone biochemistry (including magnesium, vitamin D and urate (for gout, can be normal).
Endocrinology
8. Thyroid function tests (TFTs, including TSH) — to assess for hypo- or hyperthyroidism
9. Glucose and HbA1c — to assess for type 1 or type 2 diabetes mellitus
10. 9am cortisol — to exclude adrenal insufficiency.
Immunology
11. IgA tissue transglutaminase — to assess for coeliac disease, which can present without bowel symptoms
12. Autoimmune screen – ANA, dsDNA, ENA, C3/4, Immunoglobulins (A, G, M), Rheumatoid factor (RhF), PSA (in a man, for prostate cancer); for SLE, rheumatoid arthritis and related diseases. They can present without rashes and joint pain.
13. Myeloma screen – serum protein electrophoresis (SPE) and serum free light chains (SFL)
Microbiology
14. Monospot test – for infectious mononucleosis
15. Hepatitis B/C and HIV
16. Borreliosis (Lyme disease) – antibody test
17. Syphilis (VDRL, TPHA)
18. Toxoplasmosis, Epstein-Barr virus (EBV), and cytomegalovirus (CMV) – latent viral infections.
Note. There is no specific diagnostic test (blood, sputum, nasal swab) for chronic fatigue syndrome (CFS) or Long COVID.
Other (non-blood) tests
Blood tests are not enough. The following tests may also be needed.
Urine tests
- Urinalysis (dipstick) – for protein, blood and glucose – to assess for urinary tract infection (UTI), inflammation, diabetes, or more rarely tumours
- Urinary ACR (protein).
Microbiology
- 3 sputum samples (AFBs) – tuberculosis (TB)
- Midstream specimen of urine (MSU) – M,C&S – UTI.
Radiology
- Chest x-ray – TB and other chronic lung diseases
- CT chest, abdomen and pelvis (CT CAP) – if all tests are negative.
Note. In TB the CXR can be normal and sputum not grow anything. If in doubt .. treat.
Red flag symptoms if you are tired all the time (TATT)
If, along with tiredness, you also have any of the following ‘red flags’, it is vital you see a GP sooner rather than later: unexplained weight loss; shortness of breath; recurrent fever; severe back pain; bleeding in your poo or wee, or from your gums; swollen and sore joints; or other new symptoms concerning you.
Summary
We have described 18 blood tests to do if you are tired all the time; recommended especially when there is no obvious cause. It’s important to note that most of the authors of this website are hospital doctors who deal with sicker patients. So they do more tests than GPs etc.
