Glucose Tolerance Tests

Clinical Laboratory Tests – Reference Values

Laboratory tests check a sample of patient’s blood, urine, or body tissues. A technician or  doctor analyzes the test samples to see if the results fall within the normal range. The tests use a range because what is normal differs from person to person. Many factors affect test results. These include;

  • sex
  • age
  • race
  • medical history
  • general health
  • specific foods
  • Medicines patient takes
  • How well patient followed pre-test instructions
  • variations in laboratory techniques
  • variation from one laboratory to another

Patient’s doctor may also compare patient’s results to results from previous tests. Laboratory tests are often part of a routine checkup to look for changes in patient’s health. They also help doctors to identify changes in individual’s health condition before any symptoms occur, diagnose medical conditions, plan or evaluate response to a treatments, and monitor the course of a disease over time.

Biological variation:

There are certain variations in laboratory test results that can be expected due to non-modifiable biological factors, such as age, biological rhythms and physiological changes during pregnancy. These factors may be controlled for, e.g. by selecting the most appropriate time in the day, month or year for a test, or may be taken into consideration in the interpretation of results, e.g. different reference ranges or thresholds for clinical significance depending on age, sex or pregnancy status.

 


Clinical Laboratory Tests – Reference Values

TestsSI UnitsTraditional Units
Activated partial thromboplastin time (aPTT)25-40 sec25-40 sec
Albumin (serum)35-50 g/L3.5-5.0 g/dL
Amylase (serum)25-125 IU/L25-125 U/L
Bicarbonate (HCO3) (serum)23-29 mmol/L23-29 mEq/L
Bilirubin (serum)*
Neonates (conjugated)
0-10 μmol/L0-0.6 mg/dL
Bilirubin (serum)*
Neonates (total)
1.7-180 μmol/L1.0-10.5 mg/dL
Bilirubin (serum)*
Adults (conjugated)
0-5 μmol/L0-0.3 mg/dL
Bilirubin (serum)*
Adults (total)
3-22 μmol/L0.2-1.3 mg/dL
Bleeding time (Ivy)< 5 min< 5 min
Calcium (serum)**
Total
2.10-2.50 mmol/L8.4-10.6 mg/dL
Calcium (serum)**
Ionized
1.15-1.35 mmol/L4.6-5.1 mg/dL
Calcium (urine)< 6.2 mmol/d< 250 mg/24h
Carcinoembryonic antigen (CEA) (serum)< 3.0 μg/L< 3.0 ng/mL
CO2 (total)**22-29 mmol/L22-29 mEq/L
Chloride (serum)96-106 mmol/L96-106 mEq/L
Chloride (urine)
Infant
2-10 mmol/d2-10 mEq/24h
Chloride (urine)
Child
14-50 mmol/d14-50 mEq/24h
Chloride (urine)
Adults
110-250 mmol/d110-250 mEq/24h
Cholesterol (serum)**< 5.2 mmol/L< 200 mg/dL
Cortisol (plasma)
8 AM
170-635 nmol/L6-23 μg/dL
Cortisol (plasma)
4 PM
82-413 nmol/L0.6-1.2 mg/dL
Creatinine (serum)50-110 μmol/L0.6-1.2 mg/dL
Creatinine (urine)
Males
8.8-17.6 mmol/d1.0-2.0 g/24h
Creatinine (urine)
Females
7.0-15.8 mmol/d0.8-1.8 g/24h
Creatine kinase (CK, CPK)
Males (race dependent)
20-215 IU/L20-215 U/L
Creatine kinase (CK, CPK)
Females (race dependent)
20-160 IU/L20-160 U/L
Erythrocytes (RBCs)
Children**
4.5-5.1 x 10^12/L4.5-5.1 million/mm^3
Erythrocytes (RBCs)
Males
4.6-6.2 x 10^12/L4.6-6.2 million/mm^3
Erythrocytes (RBCs)
Females
4.2-5.4 x 10^12/L4.2-5.4 million/mm^3
TestsSI UnitsTraditional Units
Ferritin (serum)20-200 μg/L20-200 ng/mL
Follicle-stimulating hormone (FSH) (plasma)
Males
1-10 IU/L1-10 mU/mL
Follicle-stimulating hormone (FSH) (plasma)
Females, premenopausal
20-50 IU/L20-50 mU/mL
Follicle-stimulating hormone (FSH) (plasma)
Females, postmenopausal
40-250 IU/L40-250 mU/mL
Glucose (fasting) (plasma or serum)3.9-6.1 mmol/L70-110 mg/dL
Growth hormone (hGH) (serum, adult) fasting0-10 μg/L0-10 ng/mL
Hematocrit
Newborn
165-195 g/L16.5-19.5 g/dL
Hematocrit
Children**
112-165 g/L11.2-16.5 g/dL
Hematocrit
Males
140-180 g/L14.0-18.0 g/dL
Hematocrit
Females
120-160 g/L12.0-16.0 g/dL
High density lipoproteins (HDL) (recommended range)> 0.91 mmol/L> 35 mg/dL
INR0.9-1.10.9-1.1
Iron (serum)
Males
13-31 μmol/L75-175 μg/dL
Iron (serum)
Females
5-29 μmol/L28-162 μg/dL
Iron binding capacity (serum) (TIBC)45-73 μmol/L250-410 μg/dL
Lactate dehydrogenase (LDH) (serum)
Adult
45-90 IU/L45-90 U/L
Lactate dehydrogenase (LDH) (serum)
Child
60-170 IU/L60-170 U/L
Lactate dehydrogenase (LDH) (serum)
> 60 years old
55-100 IU/L55-100 U/L
Leukocytes - Total3.5-12.0 x 10^9/L3500-12,000/mm^3
Neutrophils3000-5800 x 10^6/L3000-5800/mm^3
Lymphocytes1500-3000 x 10^6/L1500-3000/mm^3
Monocytes300-500 x 10^6/L300-500/mm^3
Eosinophils50-250 x 10^6/L50-250/mm^3
Basophils15-50 x 10^6/L15-50/mm^3
Low density lipoproteins (LDL) (recommended range)< 3.4 mmol/L< 130 mg/dL
Luteinizing hormone (LH) (serum)
Males
1-9 IU/L1-9 IU/L
Luteinizing hormone (LH) (serum) Females (follicular)2-10 IU/L2-10 IU/L
Luteinizing hormone (LH) (serum) Females (mid-cycle)15-65 IU/L15-65 IU/L
Luteinizing hormone (LH) (serum) Females (luteal)1-12 IU/L1-12 IU/L
Luteinizing hormone (LH) (serum) Females
(postmenopausal)
12-65 IU/L12-65 IU/L
TestsSI UnitsTraditional Units
Magnesium (serum)0.65-1.05 mmol/L1.3-2.1 mg/dL
Magnesium (urine)3.0-4.3 mmol/d6.0-8.5 mEq/24h
Mean corpuscular volume (MCV)76-100 fL76-100 μm^3
Osmolality (serum)285-295 mmol/kg285-295 mOsm/kg
Osmolality (urine)38-1400 mmol/kg38-1400 mOsm/kg
Oxygen (arterial saturation)94-99%94-99%
Parathyroid hormone (PTH)10-65 ng/L10-65 pg/mL
Partial thromboplastin time (PTT)See aPTTSee aPTT
pCO2 (arterial)35-45 mm Hg35-45 mm Hg
pH (arterial)7.35-7.457.35-7.45
Phosphatase, alkaline (serum)40-160 IU/L40-160 U/L
Phosphate
Adults
1.0-1.5 mmol/L3.0-4.5 mg/dL
Phosphate
Children
1.3-2.3 mmol/L4.0-7.0 mg/dL
Platelet count150-400 x 10^9/L50,000-400,000/mm^3
pO2 (arterial)80-100 mm Hg80-100 mm Hg
Potassium (serum)
Newborn
3.7-5.9 mmol/L3.7-5.9 mEq/L
Potassium (serum)
Infant
4.1-5.3 mmol/L4.1-5.3 mEq/L
Potassium (serum)
Child
3.4-4.7 mmol/L3.4-4.7 mEq/L
Potassium (serum)
Adult
3.5-5.1 mmol/L3.5-5.1 mEq/L
Potassium (urine)***25-125 mmol/d25-125 mEq/24h
Progesterone (serum) (adult)
Males
0.0-1.3 nmol/L0.0-0.4 ng/mL
Progesterone (serum) (adult)
Females (follicular)
0.3-4.8 nmol/L0.1-1.5 ng/mL
Progesterone (serum) (adult)
Females (luteal)
8.0-89.0 nmol/L2.5-28.0 ng/mL
Prolactin (serum)
Males
1-20 μg/L1-20 ng/mL
Prolactin (serum)
Females
1-25 μg/L1-25 ng/mL
Prostate specific antigen (PSA)0-4.0 μg/L0-4.0 ng/mL
Protein (serum)
Total
60-80 g/L6.0-8.0 g/dL
Protein (serum)
Albumin
35-55 g/L3.5-5.5 g/dL
TestsSI UnitsTraditional Units
Protein (urine)10-150 mg/d10-150 mg/24h
Prothrombin time (PT)9-12 sec9-12 sec
Reticulocytes25-75 x 10^9/L25,000-75,000/mm^3
Sedimentation rate (ESR)0-15 mm/h0-15 mm/h
Sodium (serum or plasma)135-145 mmol/L135-145 mEq/L
Sodium (urine)***40-220 mmol/d40-220 mEq/24h
Specific gravity1.003-1.0301.003-1.030
Sperm count20-150 x 10^6/mL20,000-150,000/mm^3
Testosterone
Males
9.5-30 nmol/L275-875 ng/dL
Testosterone
Females
0.8-2.6 nmol/L23-75 ng/dL
Testosterone
Pregnant females
1.3-6.6 nmol/L38-190 ng/dL
Thrombin time (plasma)< 17 sec< 17 sec
Thyroid-stimulating hormone (TSH) (serum) Adults0.4-4.8 mIU/L0.4-4.8 mIU/L
Thyroid-stimulating hormone (TSH) (serum)
Term infants: (0-1 day)
1-39 mIU/L1-39 mIU/L
Thyroid-stimulating hormone (TSH) (serum)
Term infants: (1-4 days)
1-17 mIU/L1-17 mIU/L
Thyroid-stimulating hormone (TSH) (serum)
Term infants: (2-20 weeks)
1.7-9.1 mIU/L1.7-9.1 mIU/L
Thyroid-stimulating hormone (TSH) (serum)
Term infants: (21 weeks to 20 years)
0.7-6.4 mIU/L0.7-6.4 mIU/L
Thyroxine (T4) (serum)**66-155 nmol/L5-12 μg/dL
Thyroxine, free (FT4) (serum)**13-27 pmol/L1.0-2.1 ng/dL
Transaminase (serum)
AST (SGOT)
7-40 IU/L7-40 mU/mL
Transaminase (serum)
ALT (SGPT)
5-35 IU/L5-35 mU/mL
Triiodothyronine (T3) (serum)1.1-2.9 mmol/L70-190 ng/dL
Triglycerides0.45-1.71 mmol/L40-150 mg/dL
Urea (plasma or serum)2.9-8.2 mmol/Lsee Urea nitrogen
Urea nitrogen (BUN) (plasma or serum)see Urea8-23 mg/dL
Uric acid (serum) (enzymatic)120-420 μmol/L2.0-7.0 mg/dL

These reference ranges are expressed in both SI units and traditional units for the most common laboratory tests. Most of the values apply to adults and where they differ for children, it will be indicated.
*Test values are method dependent
**Test values vary with age
***Test values are diet dependent


Pregnancy:

Physiological changes during pregnancy result in alterations in many laboratory parameters, such as blood volume, liver and renal function and hormone levels. Reference ranges for different stages of pregnancy are available for some laboratory tests, however, these ranges are often not as well defined as the general reference range. In addition, pregnancy-related changes, such as alterations in binding proteins, can affect assays differently, e.g. free hormone levels can be assay dependent. Therefore caution is recommended in interpreting results based on reference ranges and the laboratory should be contacted if there is any doubt.

When requesting a laboratory investigation in a woman who is pregnant, the gestational week should be noted on the laboratory request form.


Examples of Laboratory Values That Change with Pregnancy

IncreasesDecreases
Alpha-fetoprotein (AFP); peaks in third trimesterHaemoglobin; due to haemodilution caused by greater blood volume
Alkaline phosphatase (ALP); up to four fold increase in third trimesterFerritin; decreases as pregnancy progresses
Blood volume (mean plasma volume); increases by 30–50%FT4; may decrease slowly in late pregnancy (can be assay dependent)
Lipids; up to 40% increase in cholesterol, triglyceride levels can markedly increase in some women (due to the effect of oestrogen)Prothrombin and partial thromboplastin times
Creatinine clearance; glomerular filtration rate increases 40-60% (eGFR cannot be reliably calculated)TSH; decreases first trimester, then returns to normal (due to the effect of hCG)
ESR; increasing to 30–60 mm/h as pregnancy progressesSodium; slight decrease due to changes in blood volume and fluid homeostasis
Hormones; oestrogen, testosterone, progesterone, human chorionic gonadotrophin (hCG), prolactin
Iron binding (transferrin levels); significant increase even in a non-iron deficient woman (due to the effect of oestrogen)
White blood count; may increase to 15–18 x10^9/L