Reference ranges for common blood tests

A reference range is a set of values used by a health professional to interpret a set of medical test results. The range is usually defined as the set of values 95% of the normal population falls within.

It must be remembered that the reference range will vary, depending on the age, sex and race of a population, and even the machines the laboratory uses to do the tests. Also remember that by definition 5% of the normal population will fall outside the reference range.

These are approximate adult values that are intended as a guide to students and those interested, they are not a substitute for medical advice.

Table of contents

1 Clinical biochemistry

1.1 Electrolytes and Metabolytess
1.2 Liver function tests
1.3 Other enzymes and proteins
1.4 Other ions and trace metals
1.5 Lipids
1.6 Tumour markers
1.7 Hormones

2 Haematology

2.8 Red blood cells
2.9 White blood cells
2.10 Coagulation

3 Immunology
4 Serology

Clinical biochemistry

Electrolytes and Metabolytess

Test	Range	Comments
Sodium (Na)	130 - 145 mmol/L
Potassium (K)	3.5 - 5.0 mmol/L
Urea	2.6 - 6.8 mmol/L
Creatinine	50 - 110 μmol/L
Glucose (fasting)	4.2 - 6.1 mmol/L

Liver function tests

Total Protein	60 - 80 g/L
Albumin	30 - 50 g/L
Total Bilirubin	2 - 14 μmol/L
Direct Bilirubin	0 - 4 μmol/L
Alanine transaminase (ALT)	8 - 40 U/L	Also called serum glutamic pyruvic transaminase (SGPT)
Alkaline phosphatase (ALP)	40 - 130 U/L	Higher in children and pregnant women.
Gamma glutamyl transferase	< 50 U/L

Other enzymes and proteins

Creatine kinase (CK)
Aspartate transaminase (AST)	8 - 35 U/L
Lactate dehydrogenase (LDH)	85 - 285 U/L
Amylase	25 - 125 U/L
C-reactive protein (CRP)	<8 mg/L

Other ions and trace metals

Ionised calcium (Ca)	1.15 - 1.29 mmol/L	Some calcium is bound to albumin, thus not measured by certain techniques.
Total calcium (Ca)	2.05 - 2.55 mmol/L
Copper (Cu)	11 - 26 μmol/L
Zinc (Zn)	10 - 17 μmol/L

Lipids

Triglycerides	0.4 - 2.0 mmol/L
Total cholesterol	3.0 - 5.5 mmol/L
HDL cholesterol (male)	0.7 - 1.9 mmol/L
(female)	0.9 - 2.4 mmol/L
LDL cholesterol	2.4 - 4.0 mmol/l	Not valid when triglycerides >5.0 mmol/L.

Tumour markers

Alpha-fetoprotein (AFP)	1-15 kIU/L
CA-125	<65 kU/L
Prostate specific antigen (total PSA)	<2.0 μg/L	After age 40, normal levels increase every decade.

Hormones

Thyroid stimulating hormone (TSH)	0.5 - 4.7 mIU/L	Also called: Thyrotropin
Free thyroxine (FT₄)	9.0 - 24 pmol/L
Free triiodothyronine (FT₃)	2.5 - 5.3 pmol/L
Adrenocorticotropic hormone (ACTH)	1.3 - 15 pmol/L
Cortisol (0830 h)	250 - 850 nmol/L	Cortisol levels are higher in the morning than at night.
Cortisol (1630 h)	110 - 390 nmol/L
Prolactin (male)	<450 mIU/L
(female)	<580 mIU/L
Testosterone (male)	8 - 38 nmol/L
(male prepuberty)	0.1 - 0.5 nmol/L
(female)	0.3 - 2.5 nmol/L

Haematology

Red blood cells

Haemoglobin (Hb) (male)	130 - 180 g/L	Higher in neonates, lower in children.
(female)	115 - 160 g/L	Sex difference negligible until adulthood.
Haematocrit (Hct) (male)	0.38 - 0.52
(female)	0.35 - 0.47
Mean cell volume (MCV)	80 - 98 fL
Mean cell haemoglobin (MCH)	26 - 34 pg
Red cell count (male)	4.5 - 6.5 x10¹²/L
(female)	3.8 - 5.8 x10¹²/L
Reticulocytes	10 - 100 x10⁹/L
Erythrocyte sedimentation rate (ESR)

White blood cells

Total white blood cells	4.0 - 11.0 x10⁹/L	Higher in neonates and infants.
Neutrophils	2.0 - 7.5 x10⁹/L
Lymphocytes	1.0 - 4.0 x10⁹/L
Monocytes	0.0 - 0.8 x10⁹/L
Eosinophils	0.0 - 0.5 x10⁹/L
Basophils	0.0 - 0.2 x10⁹/L

Coagulation

Prothrombin time (PT)	7 - 10 s
INR	0.8 - 1.2	The INR is a corrected ratio of a patients PT to normal
Activated partial thromboplastin time (APTT)	29 - 41 s
Thrombin clotting time (TCT)	11 - 18 s
Fibrinogen	1.8 - 4.0 g/L
Bleeding time	2 - 8 minutes

Immunology

Antinuclear antibodies (ANA)
Extractable nuclear antigen (ENA)