Please find information by clicking on the links below:

Advice Regarding Result Interpretation:

ALLERGY TESTING -How to diagnose allergy in adults in primary care

B12 - see HAEMATINICS

BIOTIN- Biotin Interference in Roche-manufactured Immunoassays

BNP - Use of Natriuretic Peptides in the Management of Suspected Chronic Heart Failure 

CALCIUM

– Guidance for assessment of hypercalcaemia in primary care

–  Investigation of Hypocalcaemia in Primary Care

CALPROTECTIN

- The York faecal calprotectin care pathway for GPs 

 - Faecal calprotectin guidance for patients being managed in secondary care 

CORTISOL - Investigation of Adrenal Insufficiency and Cushing's Syndrome in Adults

CHLORIDE – Guidance for interpreting chloride results

CREATINE KINASE -Causes of Elevated CK

CRP - See INFLAMMATORY MARKERS

CUSHINGS SYNDROME - See CORTISOL

DIABETES - see HBA1C

ESR - See INFLAMMATORY MARKERS

ESTRADIOL – See OESTRADIOL

FAECAL CALPROTECTIN - See CALPROTECTIN

FERRITIN (high) - Investigation of elevated ferritin

FERRITIN (low) See HAEMATINICS

FOLATE - See HAEMATINCS

FREE LIGHT CHAINS – Guidance for interpreting free light chain results 

FSH - Menopause investigation and laboratory testing 

HAEMATINICS - Guidance for primary care on interpretation of haematinics (B12, folate and ferritin)

HBA1C (diagnosis of diabetes) – Guidance for when HbA1c is not suitable for diagnosis of diabetes

HBA1C (monitoring of diabetes) – Guidance for when HbA1c is not suitable for monitoring diabetes

HEART FAILURE - See BNP

HYPERKALAEMIA - See POTASSIUM

HYPONATRAEMIA - See SODIUM

HYPOMAGNESAEMIA - See MAGNESIUM

HYPOPHOSPHATAEMIA - See PHOSPHATE

IMMUNOGLOBULINS  - Guidance for investigation of low immunoglobulins 

INFLAMMATORY MARKERS – Guidance for which test to use and when

LIVER BLOOD TESTS / LIVER DISEASE - 

- Liver disease in Primary Care - Investigation of abnormal liver blood test results (adults) * Updated Fibrosis Pathway from 3rd August 2026 *

-Reference Ranges for Liver Function Tests in Pregnancy

 MAGNESIUM - Guidance for assessment and management of hypomagnesaemia in primary care 

MENOPAUSE - See FSH

METANEPHRINES (Urine) – Investigation of suspected phaeochromocytoma using 24h urine metanephrines 

MYELOMA/MGUS - See PARAPROTEINS

OSMOLALITY (Urine) - Guidance for investigation of polyuria/polydipsia

OESTRADIOL – Interpreting serum oestradiol levels 

PARAPROTEINS - Management of patients with paraprotein *Updated March 26*

PHOSPHATE -

Information for Primary Care: Management of Hypophosphataemia  

Renal Tubular Reabsorption of Phosphate

PLASMA C-PEPTIDE - Interpretation of Plasma C-Peptide Results

POTASSIUM -

- Investigating and management of hyperkalaemia (high potassium) in primary care (adults)

- Investigating and management of hypokalaemia (low potassium) in primary care (adults)

- Top tips for avoiding haemolysis

- Hyperkalaemia due to DELAYED CENTRIFUGATION 

- To enquire about obtaining a centrifuge for your surgery, please contact Carl Burkinshaw, Biochemistry network Manager: carl.burkinshaw1@nhs.net

POLYURIA- see OSMOLALITY (Urine)

PROLACTIN - Investigation of hyperprolactinaemia

 

PV - See INFLAMMATORY MARKERS

Renal Tubular Reabsorption of Phosphate - See PHOSPHATE

SODIUM - Investigation and management of hyponatraemia in primary care (Adults) 

THERAPEUTIC DRUGS - Sampling requirements for commonly requested therapeutic drugs

THYROID FUNCTION TESTS - Guidance for requesting and interpreting thyroid function tests (TFTs) 

TRACE ELEMENTS (ZINC, SELENIUM, COPPER) - A guide to requesting trace elements for adults in primary care

TROPONIN - Troponin testing in primary care

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Web Page 26 Last Updated: 12/08/2026