Reference ranges for blood tests

Reference ranges (reference intervals) for blood tests are sets of values used by a health professional to interpret a set of medical test results from blood samples. Reference ranges for blood tests are studied within the field of clinical chemistry (also known as "clinical biochemistry", "chemical pathology" or "pure blood chemistry"), the area of pathology that is generally concerned with analysis of bodily fluids.^[1][2][3]

Blood test results should always be interpreted using the reference range provided by the laboratory that performed the test.^[4]

Interpretation

A reference range is usually defined as the set of values 95 percent of the normal population falls within (that is, 95% prediction interval).^[5] It is determined by collecting data from vast numbers of laboratory tests.^[6][7]

Plasma or whole blood

In this article, all values (except the ones listed below) denote blood plasma concentration, which is approximately 60–100% larger than the actual blood concentration if the amount inside red blood cells (RBCs) is negligible. The precise factor depends on hematocrit as well as amount inside RBCs. Exceptions are mainly those values that denote total blood concentration, and in this article they are:^[8]

• All values in Hematology – red blood cells (except hemoglobin in plasma)
• All values in Hematology – white blood cells
• Platelet count (Plt)

A few values are for inside red blood cells only:

• Vitamin B₉ (folic acid/folate) in red blood cells
• Mean corpuscular hemoglobin concentration (MCHC)

Units

• Mass concentration (g/dL or g/L) is the most common measurement unit in the United States. Is usually given with dL (decilitres) as the denominator in the United States, and usually with L (litres) in, for example, Sweden.^{[citation needed]}
• Molar concentration (mol/L) is used to a higher degree in most of the rest of the world, including the United Kingdom and other parts of Europe and Australia and New Zealand.^[9]
• International units (IU) are based on measured biological activity or effect, or for some substances, a specified equivalent mass.^{[citation needed]}
• Enzyme activity (kat) is commonly used for e.g. liver function tests like AST, ALT, LD and γ-GT in Sweden.^[10]
• Percentages and time-dependent units (mol/s) are used for calculated derived parameters, e.g. for beta cell function in homeostasis model assessment or thyroid's secretory capacity.^[11]

Arterial or venous

If not otherwise specified, a reference range for a blood test is generally the venous range, as the standard process of obtaining a sample is by venipuncture. An exception is for acid–base and blood gases, which are generally given for arterial blood.^[12]

Still, the blood values are approximately equal between the arterial and venous sides for most substances, with the exception of acid–base, blood gases and drugs (used in therapeutic drug monitoring (TDM) assays).^[13] Arterial levels for drugs are generally higher than venous levels because of extraction while passing through tissues.^[13]

Usual or optimal

Reference ranges are usually given as what are the usual (or normal) values found in the population, more specifically the prediction interval that 95% of the population fall into. This may also be called standard range. In contrast, optimal (health) range or therapeutic target is a reference range or limit that is based on concentrations or levels that are associated with optimal health or minimal risk of related complications and diseases. For most substances presented, the optimal levels are the ones normally found in the population as well. More specifically, optimal levels are generally close to a central tendency of the values found in the population. However, usual and optimal levels may differ substantially, most notably among vitamins and blood lipids, so these tables give limits on both standard and optimal (or target) ranges. In addition, some values, including troponin I and brain natriuretic peptide, are given as the estimated appropriate cutoffs to distinguish healthy people from people with specific conditions, which here are myocardial infarction and congestive heart failure, respectively, for the aforementioned substances.^[14][15][16]

Variability

Further information: Reference range

References range may vary with age, sex, race, pregnancy,^[17] diet, use of prescribed or herbal drugs and stress. Reference ranges often depend on the analytical method used, for reasons such as inaccuracy, lack of standardisation, lack of certified reference material and differing antibody reactivity.^[18] Also, reference ranges may be inaccurate when the reference groups used to establish the ranges are small.^[19]

Sorted by concentration

By mass and molarity

Smaller, narrower boxes indicate a more tight homeostatic regulation when measured as standard "usual" reference range.

Reference ranges for blood tests, sorted logarithmically by mass above the scale and by molarity below. (A separate printable image is available for mass and molarity)

Hormones predominate at the left part of the scale, shown with a red at ng/L or pmol/L, being in very low concentration. There appears to be the greatest cluster of substances in the yellow part (μg/L or nmol/L), becoming sparser in the green part (mg/L or μmol/L). However, there is another cluster containing many metabolic substances like cholesterol and glucose at the limit with the blue part (g/L or mmol/L).^{[citation needed]}

The unit conversions of substance concentrations from the molar to the mass concentration scale above are made as follows:

• Numerically:

${\displaystyle {\text{molar concentration}}\times {\text{molar mass}}={\text{mass concentration}}}$

• Measured directly in distance on the scales:

${\displaystyle \log _{10}{\frac {\text{molar mass}}{1000}}={\text{distance to right (decades)}}}$,

where distance is the direct (not logarithmic) distance in number of decades or "octaves" to the right the mass concentration is found. To translate from mass to molar concentration, the dividend (molar mass and the divisor (1000) in the division change places, or, alternatively, distance to right is changed to distance to left. Substances with a molar mass around 1000g/mol (e.g. thyroxine) are almost vertically aligned in the mass and molar images. Adrenocorticotropic hormone, on the other hand, with a molar mass of 4540,^[20] is 0.7 decades to the right in the mass image. Substances with molar mass below 1000g/mol (e.g. electrolytes and metabolites) would have "negative" distance, that is, masses deviating to the left. Many substances given in mass concentration are not given in molar amount because they haven't been added to the article.

The diagram above can also be used as an alternative way to convert any substance concentration (not only the normal or optimal ones) from molar to mass units and vice versa for those substances appearing in both scales, by measuring how much they are horizontally displaced from one another (representing the molar mass for that substance), and using the same distance from the concentration to be converted to determine the equivalent concentration in terms of the other unit. For example, on a certain monitor, the horizontal distance between the upper limits for parathyroid hormone in pmol/L and pg/mL may be 7 cm, with the mass concentration to the right. A molar concentration of, for example, 5 pmol/L would therefore correspond to a mass concentration located 7 cm to the right in the mass diagram, that is, approximately 45 pg/mL.

By units

Units do not necessarily imply anything about molarity or mass.

A few substances are below this main interval, e.g. thyroid stimulating hormone, being measured in mU/L, or above, like rheumatoid factor and CA19-9, being measured in U/mL.

By enzyme activity

White blood cells

Sorted by category

Ions and trace metals

Further information: Trace metal and Metals in medicine

Included here are also related binding proteins, like ferritin and transferrin for iron, and ceruloplasmin for copper.

Test	Lower limit	Upper limit	Unit*	Comments
Sodium (Na)	135,[21] 137[10][22]	145,[10][22] 147[21]	mmol/L or mEq/L[21]	See hyponatremia or hypernatremia
	310,[23] 320[23]	330,[23] 340[23]	mg/dL
Potassium (K)	3.5,[10][21] 3.6[22]	5.0,[10][21][22] 5.1	mmol/L or mEq/L[21]	See hypokalemia or hyperkalemia
	14[24]	20[24]	mg/dL
Chloride (Cl)	95,[21] 98,[25] 100[10]	105,[21] 106,[25] 110[10]	mmol/L or mEq/L[21]	See hypochloremia or hyperchloremia
	340[26]	370[26]	mg/dL
Ionized calcium (Ca)	1.03,[27] 1.10[10]	1.23,[27] 1.30[10]	mmol/L	See hypocalcaemia or hypercalcaemia
4.1,[28] 4.4[28]	4.9,[28] 5.2[28]	mg/dL
Total calcium (Ca)	2.1,[21][29] 2.2[10]	2.5,[10][29] 2.6,[29] 2.8[21]	mmol/L
8.4,[21] 8.5[30]	10.2,[21] 10.5[30]	mg/dL
Total serum iron (TSI) – male	65,[31] 76[22]	176,[31] 198[22]	μg/dL	See hypoferremia or the following: iron overload (hemochromatosis), iron poisoning, siderosis, hemosiderosis, hyperferremia
	11.6,[32][33] 13.6[33]	30,[32] 32,[33] 35[33]	μmol/L
Total serum iron (TSI) – female	26,[22] 50[31]	170[22][31]	μg/dL
4.6,[33] 8.9[32]	30.4[32]	μmol/L
Total serum iron (TSI) – newborns	100[31]	250[31]	μg/dL
18[33]	45[33]	μmol/L
Total serum iron (TSI) – children	50[31]	120[31]	μg/dL
9[33]	21[33]	μmol/L
Total iron-binding capacity (TIBC)	240,[31] 262[22]	450,[31] 474[22]	μg/dL
43,[33] 47[33]	81,[33] 85[33]	μmol/L
Transferrin	190,[34] 194,[10] 204[22]	326,[10] 330,[34] 360[22]	mg/dL
	25[35]	45[35]	μmol/L
Transferrin saturation	20[31]	50[31]	%
Ferritin – Males and postmenopausal females	12[36]	300[36][37]	ng/mL or μg/L
	27[38]	670[38]	pmol/L
Ferritin – premenopausal females	12[36]	150[36] – 200[37]	ng/mL or μg/L
	27[38]	330[38] – 440[38]	pmol/L
Ammonia	10,[39] 20[40]	35,[39] 65[40]	μmol/L	See hypoammonemia and hyperammonemia
	17,[41] 34[41]	60,[41] 110[41]	μg/dL
Copper (Cu)	70[30]	150[30]	μg/dL	See hypocupremia or hypercupremia
	11[42][43]	24[42]	μmol/L
Ceruloplasmin	15[30]	60[30]	mg/dL
	1[44]	4[44]	μmol/L
Phosphate (HPO42−)	0.8	1.5[45]	mmol/L	See hypophosphatemia or hyperphosphatemia
Inorganic phosphorus (serum)	1.0[21]	1.5[21]	mmol/L
	3.0[21]	4.5[21]	mg/dL
Zinc (Zn)	60,[46] 72[47]	110,[47] 130[46]	μg/dL	See zinc deficiency or zinc poisoning
	9.2,[48] 11[10]	17,[10] 20[48]	μmol/L
Magnesium	1.5,[30] 1.7[49]	2.0,[30] 2.3[49]	mEq/L or mg/dL	See hypomagnesemia or hypermagnesemia
	0.6,[50] 0.7[10]	0.82,[50] 0.95[10]	mmol/L

• Note: Although 'mEq' for mass and 'mEq/L' are sometimes used in the United States and elsewhere, they are not part of SI and are now considered redundant.

Acid–base and blood gases

Further information: Acid–base homeostasis

Further information: Arterial blood gas test and Arterial blood gas test § Parameters and reference ranges

If arterial/venous is not specified for an acid–base or blood gas value, then it generally refers to arterial, and not venous which otherwise is standard for other blood tests.^{[citation needed]}

Acid–base and blood gases are among the few blood constituents that exhibit substantial difference between arterial and venous values.^[13] Still, pH, bicarbonate and base excess show a high level of inter-method reliability between arterial and venous tests, so arterial and venous values are roughly equivalent for these.^[51]

Test	Arterial/Venous	Lower limit	Upper limit	Unit
pH	Arterial	7.34,[22] 7.35[21]	7.44,[22] 7.45[21]
	Venous	7.31[52]	7.41[52]
[H+]	Arterial	36[21]	44[21]	nmol/L
		3.6[53]	4.4[53]	ng/dL
Base excess	Arterial & venous[52]	−3[52]	+3[52]	mEq/L
Oxygen partial pressure (pO2)	Arterial pO2	10,[21] 11[54]	13,[54] 14[21]	kPa
		75,[21][22] 83[30]	100,[22] 105[21]	mmHg or torr
	Venous	4.0[54]	5.3[54]	kPa
		30[52]	40[52]	mmHg or torr
Oxygen saturation	Arterial	94,[52] 95,[25] 96[30]	100[25][30]	%
	Venous	Approximately 75[25]
Carbon dioxide partial pressure (pCO2)	Arterial PaCO2	4.4,[21] 4.7[54]	5.9,[21] 6.0[54]	kPa
		33,[21] 35[22]	44,[21] 45[22]	mmHg or torr
	Venous	5.5,[54]	6.8[54]	kPa
		41[52]	51[52]	mmHg or torr
Absolute content of carbon dioxide (CO2)	Arterial	23[52]	30[52]	mmol/L
		100[55]	132[55]	mg/dL
Bicarbonate (HCO3−)	Arterial & venous	18[30]	23[30]	mmol/L
		110[56]	140[56]	mg/dL
Standard bicarbonate (SBCe)	Arterial & venous	21, 22[21]	27, 28[21]	mmol/L or mEq/L[21]
		134[56]	170[56]	mg/dL

Liver function

Further information: Liver function tests

Test	Patient type	Lower limit	Upper limit	Unit	Comments
Total protein (TotPro)		60,[21] 63[22]	78,[21] 82,[22] 84[30]	g/L	See serum total protein Interpretation
Albumin		35[21][57]	48,[22] 55[21]	g/L	See hypoalbuminemia
		3.5[22]	4.8,[22] 5.5[21]	U/L
		540[58]	740[58]	μmol/L
Globulins		23[21]	35[21]	g/L
Total bilirubin		1.7,[59] 2,[21] 3.4,[59] 5[10]	17,[21][59] 22,[59] 25[10]	μmol/L
		0.1,[21] 0.2,[22] 0.29[60]	1.0,[21][30] 1.3,[22] 1.4[60]	mg/dL
Direct/conjugated bilirubin		0.0[21] or N/A[10]	5,[21] 7[10][59]	μmol/L
		0[21][22]	0.3,[21][22] 0.4[30]	mg/dL
Alanine transaminase (ALT/ALAT[10])		5,[61] 7,[22] 8[21]	20,[21] 21,[25] 56[22]	U/L	Also called serum glutamic pyruvic transaminase (SGPT)
	Female	0.15[10]	0.75[10]	μkat/L
	Male	0.15[10]	1.1[10]
Aspartate transaminase (AST/ASAT[10])	Female	6[62]	34[62]	IU/L	Also called serum glutamic oxaloacetic transaminase (SGOT)
		0.25[10]	0.60[10]	μkat/L
	Male	8[62]	40[62]	IU/L
		0.25[10]	0.75[10]	μkat/L
Alkaline phosphatase (ALP)		0.6[10]	1.8[10]	μkat/L
	Female	42[61]	98[61]	U/L
	Male	53[61]	128[61]
Gamma glutamyl transferase (GGT)		5,[61] 8[22]	40,[61] 78[22]	U/L
	Female		0.63[63]	μkat/L
	Male		0.92[63]	μkat/L

Cardiac tests

Test	Patient type	Lower limit	Upper limit	Unit	Comments
Creatine kinase (CK)	Male	24,[64] 38,[22] 60[61]	174,[30] 320[61]	U/L or ng/mL
		0.42[65]	1.5[65]	μkat/L
	Female	24,[64] 38,[22] 96[30]	140,[30] 200[61]	U/L or ng/mL
		0.17[65]	1.17[65]	μkat/L
CK-MB		0	3,[22] 3.8,[10] 5[61]	ng/mL or μg/L[10]
Myoglobin	Female	1[66]	66[66]	ng/mL or μg/L
	Male	17[66]	106[66]
Cardiac troponin T (low sensitive)			0.1[14]	ng/mL	99th percentile cutoff
Cardiac troponin I (high sensitive)			0.03[14]	ng/mL	99th percentile cutoff
Cardiac troponin T (high sensitive)	Male		0.022[14]	ng/mL	99th percentile cutoff
	Female		0.014[14]	ng/mL	99th percentile cutoff
	newborn/infants		not established		more than adults [67][68]

Brain natriuretic peptide (BNP) -more detailed ranges in BNP article
Interpretation	Range / Cutoff
Congestive heart failure unlikely	< 100 pg/mL[15][16]
"Gray zone"	100–500 pg/mL[15][16]
Congestive heart failure likely	> 500 pg/mL[15][16]

NT-proBNP -more detailed ranges in NT-proBNP article
Interpretation	Age	Cutoff
Congestive heart failure likely	< 75 years	> 125 pg/mL[69]
	> 75 years	> 450pg/mL[69]

Lipids

Further information: Blood lipids

Test	Patient type	Lower limit	Upper limit	Unit	Therapeutic target
Triglycerides	10–39 years	54[30]	110[30]	mg/dL	< 100 mg/dL[70] or 1.1 mmol/L[70]
		0.61[71]	1.2[71]	mmol/L
	40–59 years	70[30]	150[30]	mg/dL
		0.77[71]	1.7[71]	mmol/L
	> 60 years	80[30]	150[30]	mg/dL
		0.9[71]	1.7[71]	mmol/L
Total cholesterol		3.0,[72] 3.6[21][72]	5.0,[10][73] 6.5[21]	mmol/L	< 3.9 mmol/L[70]
		120,[22] 140[21]	200,[22] 250[21]	mg/dL	< 150 mg/dL[70]
HDL cholesterol	Female	1.0,[74] 1.2,[10] 1.3[72]	2.2[74]	mmol/L	> 1.0[74] or 1.6[72] mmol/L 40[75] or 60[76] mg/dL
		40,[75] 50[77]	86[75]	mg/dL
HDL cholesterol	Male	0.9[10][74]	2.0[74]	mmol/L
		35[75]	80[75]	mg/dL
LDL cholesterol (Not valid when triglycerides >5.0 mmol/L)		2.0,[74] 2.4[73]	3.0,[10][73] 3.4[74]	mmol/L	< 2.5 mmol/L[74]
		80,[75] 94[75]	120,[75] 130[75]	mg/dL	< 100 mg/dL[75]
LDL/HDL quotient		n/a	5[10]	(unitless)

Tumour markers

Further information: Tumour markers

Test	Patient type	Cutoff	Unit	Comments
Alpha fetoprotein (AFP)		44[22]	ng/mL or μg/L	Hepatocellular carcinoma or testicular cancer
Beta human chorionic gonadotrophin (β-hCG)	In males and non-pregnant females	5[22]	IU/L or mU/mL	choriocarcinoma
CA19-9		40[22]	U/mL	Pancreatic cancer
CA-125		30,[78] 35[79]	kU/L or U/mL
Carcinoembryonic antigen (CEA)	Non-smokers, 50 years	3.4,[10] 3.6[80]	μg/L
	Non-smokers, 70 years	4.1[80]
	Smokers	5[81]
Prostate specific antigen (PSA)	40–49 years	1.2–2.9[82]	μg/L[10][22] or ng/mL[30]	More detailed cutoffs in PSA – Serum levels
	70–79 years, non-African-American	4.0–9.0[82]
	70–79 years, African-American	7.7–13[82]
PAP		3[30]	units/dL (Bodansky units)
Calcitonin		5,[83] 15[83]	ng/L or pg/mL	Cutoff against medullary thyroid cancer[83] More detailed cutoffs in Calcitonin article

Endocrinology

Thyroid hormones

Further information: Thyroid function tests

Test	Patient type	Lower limit	Upper limit	Unit
Thyroid stimulating hormone (TSH or thyrotropin)	Adults – standard range	0.3,[10] 0.4,[22] 0.5,[30] 0.6[84]	4.0,[10] 4.5,[22] 6.0[30]	mIU/L or μIU/mL
	Adults – optimal range	0.3,[85] 0.5[86]	2.0,[86] 3.0[85]
	Infants	1.3[87]	19[87]
Free thyroxine (FT4) -more detailed ranges in Thyroid function tests article	Normal adult	0.7,[88] 0.8[22]	1.4,[88] 1.5,[22] 1.8[89]	ng/dL
		9,[10][90] 10,[91] 12[92]	18,[10][90] 23[92]	pmol/L
	Child/Adolescent 31 d – 18 y	0.8[88]	2.0[88]	ng/dL
		10[90]	26[90]	pmol/L
	Pregnant	0.5[88]	1.0[88]	ng/dL
		6.5[90]	13[90]	pmol/L
Total thyroxine		4,[91] 5.5[22]	11,[91] 12.3[22]	μg/dL
		60[91][92]	140,[91] 160[92]	nmol/L
Free triiodothyronine (FT3)	Normal adult	0.2[91]	0.5[91]	ng/dL
		3.1[93]	7.7[93]	pmol/L
	Children 2-16 y	0.1[94]	0.6[94]	ng/dL
		1.5[93]	9.2[93]	pmol/L
Total triiodothyronine		60,[22] 75[91]	175,[91] 181[22]	ng/dL
		0.9,[10] 1.1[91]	2.5,[10] 2.7[91]	nmol/L
Thyroxine-binding globulin (TBG)		12[22]	30[22]	mg/L
Thyroglobulin (Tg)		1.5[91]	30[91]	pmol/L
		1[91]	20[91]	μg/L

Sex hormones

Further information: Sex steroid

The diagrams below take inter-cycle and inter-woman variability into account in displaying reference ranges for estradiol, progesterone, FSH and LH.

Levels of estradiol (the main estrogen), progesterone, luteinizing hormone and follicle-stimulating hormone during the menstrual cycle.^[95]

Test	Patient type	Lower limit	Upper limit	Unit
Dihydrotestosterone	adult male	30	85	ng/dL
Testosterone	Male, overall	8,[96] 10[97]	27,[96] 35[97]	nmol/L
		230,[98] 300[99]	780–1000[98][99]	ng/dL
	Male < 50 years	10[10]	45[10]	nmol/L
		290[98]	1300[98]	ng/dL
	Male > 50 years	6.2[10]	26[10]	nmol/L
		180[98]	740[98]	ng/dL
	Female	0.7[97]	2.8–3.0[97][10]	nmol/L
		20[99]	80–85[99][98]	ng/dL
17α-Hydroxyprogesterone	male	0.06[30]	3.0[30]	mg/L
		0.18[100]	9.1[100]	μmol/L
	Female (Follicular phase)	0.2[30]	1.0[30]	mg/L
		0.6[100]	3.0[100]	μmol/L
Follicle-stimulating hormone (FSH) -more detailed menstrual cycle ranges in separate diagram	Prepubertal	<1[101]	3[101]	IU/L
	Adult male	1[101]	8[101]
	Adult female (follicular and luteal phase)	1[101]	11[101]
	Adult female (Ovulation)	6[101] 95% PI (standard)	26[101] 95% PI)
		5[102] 90% PI (used in diagram)	15[102] (90% PI)
	Post-menopausal female	30[101]	118[101]
Luteinizing hormone (LH) -more detailed menstrual cycle ranges in separate diagram	Female, peak	20[102] 90% PI (used in diagram)	75[102] (90% PI)	IU/L
	Female, post-menopausal	15[103]	60[103]
	Male aged 18+	2[104]	9[104]
Estradiol (an estrogen) -more detailed ranges in estradiol article	Adult male	50[105]	200[105]	pmol/L
		14[106]	55[106]	pg/mL
	Adult female (day 5 of follicular phase, and luteal phase)	70[105]	500,[105] 600[105]	pmol/L
		19[106]	140,[106] 160[106]	pg/mL
	Adult female – free (not protein bound)	0.5[107]	9[107]	pg/mL
		1.7[107]	33[107]	pmol/L
	Post-menopausal female	N/A[105]	< 130[105]	pmol/L
		N/A[106]	< 35[106]	pg/mL
Progesterone -more detailed ranges in Progesterone article	Female in mid-luteal phase (day 21–23)	17,[102] 35[108]	92[108]	nmol/L
		6,[102] 11[109]	29[109]	ng/mL
Androstenedione	Adult male and female	60[103]	270[103]	ng/dL
	Post-menopausal female		< 180[103]
	Prepubertal		< 60[103]
Dehydroepiandrosterone sulfate -more detailed ranges in DHEA-S article	Adult male and female	30[110]	400[110]	μg/dL
SHBG -more detailed ranges in SHBG article	Adult female	40[111]	120[111]	nmol/L
	Adult male	20[111]	60[111]
Anti-Müllerian hormone (AMH) -more detailed ranges in AMH article	13–45 years	0.7[112]	20[112]	ng/mL
		5[113]	140[113]	pmol/L

Other hormones

Further information: Hormones

Test	Patient type	Lower limit	Upper limit	Unit
Adrenocorticotropic hormone (ACTH)		2.2[114]	13.3[114]	pmol/L
		20[22]	100[22]	pg/mL
Cortisol	09:00 am	140[115]	700[115]	nmol/L
		5[116]	25[116]	μg/dL
	Midnight	80[115]	350[115]	nmol/L
		2.9[116]	13[116]	μg/dL
Growth hormone (fasting)		0	5[21]	ng/mL
Growth hormone (arginine stimulation)		7[21]	n/a	ng/mL
IGF-1 -more detailed ranges in IGF-1 article	Female, 20 yrs	110[117]	420[117]	ng/mL
	Female, 75 yrs	55[117]	220[117]
	Male, 20 yrs	160[117]	390[117]
	Male, 75 yrs	48[117]	200[117]
Prolactin -more detailed ranges in Prolactin article	Female	71,[118] 105[118]	348,[118] 548[118]	mIU/L
		3.4,[118] 3.9[118]	16.4,[118] 20.3[118]	μg/L
	Male	58,[118] 89[118]	277,[118] 365[118]	mIU/L
		2.7,[118] 3.3[118]	13.0,[118] 13.5[118]	μg/L
Parathyroid hormone (PTH)		10,[119] 17[120]	65,[119] 70[120]	pg/mL
		1.1,[10] 1.8[121]	6.9,[10] 7.5[121]	pmol/L
25-hydroxycholecalciferol (a vitamin D) – Standard reference range		8,[30][122] 9[122]	40,[122] 80[30]	ng/mL
		20,[123] 23[124]	95,[124] 150[123]	nmol/L
25-hydroxycholecalciferol – Therapeutic target range		30,[125] 40[126]	65,[126] 100[125]	ng/mL
		85,[70] 100[126]	120,[70] 160[126]	nmol/L
Plasma renin activity		0.29,[127] 1.9[128]	3.7[127][128]	ng/(mL·h)
		3.3,[129] 21[130]	41[129][130]	mcU/mL
Aldosterone -more detailed ranges in Aldosterone article	Adult		19,[129] 34.0[129]	ng/dL
			530,[131] 940[131]	pmol/L
Aldosterone-to-renin ratio -more detailed ranges in Aldosterone/renin ratio article	Adult		13.1,[132] 35.0[132]	ng/dL per ng/(mL·h)
			360,[132] 970[132]	pmol/liter per μg/(L·h)

Vitamins

Also including the vitamin B₁₂)-related amino acid homocysteine.

Test	Patient type	Standard range		Optimal range		Unit
		Lower limit	Upper limit	Lower limit	Upper limit
Vitamin A		30[30]	65[30]			μg/dL
Vitamin B9 (Folic acid/Folate) – Serum	Age > 1 year	3.0[133]	16[133]	5[134]		ng/mL or μg/L
		6.8[135]	36[135]	11[135]		nmol/L
Vitamin B9 (Folic acid/Folate) – Red blood cells		200[133]	600[133]			ng/mL or μg/L
		450[135]	1400[135]			nmol/L
	Pregnant			400[133]		ng/mL or μg/L
				900[133]		nmol/L
Vitamin B12 (Cobalamin)		130,[136] 160[137]	700,[136] 950[137]			ng/L
		100,[138] 120[10]	520,[138] 700[10]			pmol/L
Homocysteine -more detailed ranges in Homocysteine article		3.3,[139] 5.9[139]	7.2,[139] 15.3[139]		6.3[70]	μmol/L
		45,[140] 80[140]	100,[140] 210[140]		85[70]	μg/dL
Vitamin C (Ascorbic acid)		0.4[30]	1.5[30]	0.9[70]		mg/dL
		23[141]	85[141]	50[70]		μmol/L
25-hydroxycholecalciferol (a vitamin D)		8,[30][122] 9[122]	40,[122] 80[30]	30,[125] 40[126]	65,[126] 100[125]	ng/mL
		20,[123] 23[124]	95,[124] 150[123]	85,[70] 100[126]	120,[70] 160[126]	nmol/L
Vitamin E				28[70]		μmol/L
				1.2[70]		mg/dL

Toxic Substances

Test	Limit type	Limit	Unit
Lead	Optimal health range	< 20[25] or 40[30]	μg/dL
Blood ethanol content	Limit for drunk driving	0,[142] 0.2,[142] 0.8[142]	‰ or g/L
		17.4[143]	mmol/L

Hematology

Red blood cells

These values (except Hemoglobin in plasma) are for total blood and not only blood plasma.

Test	Patient	Lower limit	Upper limit	Unit	Comments
Hemoglobin (Hb)	Male	2.0,[144] 2.1[21][145]	2.5,[144] 2.7[21][145]	mmol/L	Higher in neonates, lower in children.
		130,[10] 132,[22] 135[21]	162,[22] 170,[10] 175[21]	g/L
	Female	1.8,[144] 1.9[21][145]	2.3,[144] 2.5[21][144][145]	mmol/L	Sex difference negligible until adulthood.
		120[10][21][22]	150,[10] 152,[22] 160[21][30]	g/L
Hemoglobin subunits (sometimes displayed simply as "Hemoglobin")	Male	8.0,[146] 8.4[146]	10.0,[146] 10.8[146]	mmol/L	4 per hemoglobin molecule
	Female	7.2,[146] 7.6[146]	9.2,[146] 10.0[146]
Hemoglobin in plasma		0.16[21]	0.62[21]	μmol/L	Normally diminutive compared with inside red blood cells
		1	4	mg/dL
Glycated hemoglobin (HbA1c)	< 50 years	3.6[10]	5.0[10]	% of Hb
	> 50 years	3.9[10]	5.3[10]
Haptoglobin	< 50 years	0.35[10]	1.9[10]	g/L
	> 50 years	0.47[10]	2.1[10]
Hematocrit (Hct)	Male	0.39,[10] 0.4,[22] 0.41,[21] 0.45[30]	0.50,[10] 0.52,[22] 0.53,[21] 0.62[30]	L/L
	Female	0.35,[10] 0.36,[21] 0.37[22][30]	0.46,[10][21][22] 0.48[30]	L/L
	Child	0.31[22]	0.43[22]	L/L
Mean corpuscular volume (MCV)	Male	76,[30] 82[22]	100,[30] 102[22]	fL	Cells are larger in neonates, though smaller in other children.
	Female	78[22]	101[22]	fL
Red blood cell distribution width (RDW)		11.5[22]	14.5[22]	%
Mean cell hemoglobin (MCH)		0.39[21]	0.54[21]	fmol/cell
		25,[21] 27[10][30]	32,[30] 33,[10] 35[21]	pg/cell
Mean corpuscular hemoglobin concentration (MCHC)		4.8,[147] 5.0[147]	5.4,[147] 5.6[147]	mmol/L
		31,[22] 32[10][30]	35,[22] 36[10][30]	g/dL or %[note 1]
Erythrocytes/Red blood cells (RBC)	Male	4.2,[30] 4.3[10][21][22]	5.7,[10] 5.9,[21] 6.2,[22] 6.9[30]	x1012/L or million/mm3
	Female	3.5,[21] 3.8,[22] 3.9[10]	5.1,[10] 5.5[21][22]
	Infant/Child	3.8[22]	5.5[22]
Reticulocytes	Adult	26[10]	130[10]	x109/L
		0.5[21][22]	1.5[21][22]	% of RBC
	Newborn	1.1[22]	4.5[22]	% of RBC
	Infant	0.5[22]	3.1[22]	% of RBC
Immature reticulocyte fraction (IRF)	Adult	1.6[148]	12.1[148]	% of reticulocytes
Reticulocyte hemoglobin equivalent	Adult	30.0[148]	37.6[148]	%
		24.1[149]	35.8[149]	pg
Immature platelet fraction (IPF)	Adult	0.8[148]	5.6[148]	%

White blood cells

These values are for total blood and not only blood plasma.

Test	Patient type	Lower limit	Upper limit	Unit
White Blood Cell Count (WBC)	Adult	3.5,[10] 3.9,[150] 4.1,[22] 4.5[21]	9.0,[10] 10.0,[150] 10.9,[22] 11[21]	x109/L x103/mm3 or x103/μL
	Newborn	9[151]	30[151]
	1 year old	6[151]	18[151]
Neutrophil granulocytes (A.K.A. grans, polys, PMNs, or segs)	Adult	1.3,[10] 1.8,[150] 2[151]	5.4,[10] 7,[150] 8[151]	x109/L
		45–54[21]	62,[21] 74	% of WBC
	Newborn	6[151]	26[151]	x109/L
Neutrophilic band forms	Adult		0.7[151]	x109/L
		3[21]	5[21]	% of WBC
Lymphocytes	Adult	0.7,[10] 1.0[150][151]	3.5,[150] 3.9,[10] 4.8[151]	x109/L
		16–25[21]	33,[21] 45	% of WBC
	Newborn	2[151]	11[151]	x109/L
Monocytes	Adult	0.1,[10] 0.2[152][153]	0.8[10][151][153]	x109/L
		3,[21] 4.0	7,[21] 10	% of WBC
	Newborn	0.4[151]	3.1[151]	x109/L
Mononuclear leukocytes (Lymphocytes + monocytes)	Adult	1.5	5	x109/L
		20	35	% of WBC
CD4+ T cells	Adult	0.4,[22] 0.5[25]	1.5,[25] 1.8[22]	x109/L
Eosinophil granulocytes	Adult	0.0,[10] 0.04[153]	0.44,[153] 0.45,[151] 0.5[10]	x109/L
		1[21]	3,[21] 7	% of WBC
	Newborn	0.02[151]	0.85[151]	x109/L
Basophil granulocytes	Adult	40[150]	100,[10][153] 200,[151] 900[150]	x106/L
		0.0	0.75,[21] 2	% of WBC
	Newborn		0.64[151]	x109/L

Coagulation

Test	Lower limit	Upper limit	Unit	Comments
Thrombocyte/Platelet count (Plt)	140,[22] 150[10][21]	350,[10][30] 400,[21] 450[22]	x109/L or x1000/μL
Mean platelet volume (MPV)	7.2,[154] 7.4,[155] 7.5[156]	10.4,[155] 11.5,[156] 11.7[154]	fL
Prothrombin time (PT)	10,[25] 11,[21][157] 12[22]	13,[25] 13.5,[157] 14,[22] 15[21]	s	PT reference varies between laboratory kits – INR is standardised
INR	0.9[10]	1.2[10]		The INR is a corrected ratio of a patient's PT to normal
Activated partial thromboplastin time (APTT)	18,[22] 30[10][25]	28,[22] 42,[10] 45[25]	s
Thrombin clotting time (TCT)	11	18	s
Fibrinogen	1.7,[22] 2.0[10]	3.6,[10] 4.2[22]	g/L
Antithrombin	0.80[10]	1.2[10]	kIU/L
	0.15,[158] 0.17[159]	0.2,[158] 0.39[159]	mg/mL
Bleeding time	2	9	minutes
Viscosity	1.5[160]	1.72[160]	cP

Immunology

Acute phase proteins

Acute phase proteins are markers of inflammation.

Test	Patient	Lower limit	Upper limit	Unit	Comments
Erythrocyte sedimentation rate (ESR)	Male	0	Age÷2[161]	mm/h	ESR increases with age and tends to be higher in females.[162]
	Female		(Age+10)÷2[161]
C-reactive protein (CRP)			5,[10][163] 6[164]	mg/L
			200,[165] 240[165]	nmol/L
Alpha 1-antitrypsin (AAT)		20,[166] 22[167]	38,[167] 53[166]	μmol/L
		89,[168] 97[10]	170,[10] 230[168]	mg/dL
Procalcitonin			0.15[169]	ng/mL or μg/L

Isotypes of antibodies

Further information: Antibody

Test	Patient	Lower limit	Upper limit	Unit
IgA	Adult	70,[10] 110[170]	360,[10] 560[170]	mg/dL
IgD		0.5[170]	3.0[170]
IgE		0.01[170]	0.04[170]
IgG		800[170]	1800[170]
IgM		54[170]	220[170]

Autoantibodies

For clinical associations, see Autoantibody.

Autoantibodies are usually absent or very low, so instead of being given in standard reference ranges, the values usually denote where they are said to be present, or whether the test is a positive test. There may also be an equivocal interval, where it is uncertain whether there is a significantly increased level.

Test	Negative	Equivocal	Positive	Unit
anti-SS-A (Ro)	< 1.0[171]	n/a	≥ 1.0[171]	Units (U)
anti-SS-B (La)	< 1.0[172]	n/a	≥ 1.0[172]
Anti ds-DNA	< 30.0[173]	30.0–75.0[173]	> 75.0[173]	International Units per millilitre (IU/mL)
Anti ss-DNA	< 8[174]	8–10[174]	> 10[174]	Units per millilitre (U/mL)
Anti-histone antibodies	< 25[174]	n/a[174]	> 25[174]
Cytoplasmic anti-neutrophil cytoplasmic antibodies (c-ANCA)	< 20[174]	21–30[174]	> 30[174]
Perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA)	< 5[174]	n/a	> 5[174]
Anti-mitochondrial antibodies (AMA)	< 0.1[175]	0.1-0.9[175]	≥ 1.0[175]	Units (U)
Rheumatoid factor (RF)	< 20	20–30	> 30[22]	Units per millilitre (U/mL)
Antistreptolysin O titre (ASOT) in preschoolers			> 100
ASOT at school age			> 250[22]
ASOT in adults			> 125[22]

Test	Negative	Low/weak positive	Moderate positive	High/strong positive	Unit
Anti-phospholipid IgG	< 20[174]	20–30[174]	31–50[174]	> 51[174]	GPLU/mL[174]
Anti-phospholipid IgM	< 1.5[174]	1.5–2.5[174]	2–9.9[174]	> 10[174]	MPL /mL[174]
Anti-phospholipid IgA	< 10[174]	10–20[174]	21–30[174]	> 31[174]	arb U/mL[174]
Anti-citrullinated protein antibodies	< 20[174]	20–39[174]	40–59[174]	> 60[174]	EU[174]

Other immunology

Test	Lower limit	Upper limit	Unit
Serum free light chains (FLC): kappa/lambda ratio	0.26[176]	1.65[176]	(unitless)

Other enzymes and proteins

Test	Lower limit	Upper limit	Unit	Comments
Serum total protein	60,[21] 63[22]	78,[21] 82,[22] 84[30]	g/L	Further information: Serum total protein § Interpretation
Lactate dehydrogenase (LDH)	50[30]	150[30]	U/L
	0.4[61]	1.7[61]	μmol/L
	1.8[10]	3.4[10]	μkat/L	< 70 years old[10]
Amylase	25,[21] 30,[22] 53[30]	110,[22] 120,[177] 123,[30] 125,[21] 190[61]	U/L
	0.15[10]	1.1[10]	μkat/L
	200[165]	240[165]	nmol/L
D-dimer -more detailed ranges in D-dimer article	n/a	500[178]	ng/mL	Higher in pregnant women[179]
		0.5[10]	mg/L
Lipase	7,[22] 10,[30] 23[61]	60,[22] 150,[30] 208[61]	U/L
Angiotensin-converting enzyme (ACE)	23[61]	57[61]	U/L
Acid phosphatase		3.0[61]	ng/mL
Eosinophil cationic protein (ECP)	2.3[10]	16[10]	μg/L

Other electrolytes and metabolites

Electrolytes and metabolites: For iron and copper, some related proteins are also included.

Test	Patient type	Lower limit	Upper limit	Unit	Comments
Osmolality		275,[21] 280,[30] 281[10]	295,[21] 296,[30] 297[10]	mOsm/kg	Plasma weight excludes solutes
Osmolarity		Slightly less than osmolality		mOsm/L	Plasma volume includes solutes
Urea		3.0[180]	7.0[180]	mmol/L	BUN – blood urea nitrogen
		7[21]	18,[21] 21[22]	mg/dL
* Uric acid[22]		0.18[21]	0.48[21]	mmol/L
	Female	2.0[30]	7.0[30]	mg/dL
	Male	2.1[30]	8.5[30]	mg/dL
Creatinine	Male	60,[10] 68[181]	90,[10] 118[181]	μmol/L	May be complemented with creatinine clearance
		0.7,[182] 0.8[182]	1.0,[182] 1.3[182]	mg/dL
	Female	50,[10] 68[181]	90,[10] 98[181]	μmol/L
		0.6,[182] 0.8[182]	1.0,[182] 1.1[182]	mg/dL
BUN/Creatinine Ratio		5[30]	35[30]	–
Plasma glucose (fasting)		3.8,[21] 4.0[10]	6.0,[10] 6.1[183]	mmol/L	See also glycated hemoglobin (in hematology)
		65,[22] 70,[21] 72[184]	100,[183] 110[30]	mg/dL
Full blood glucose (fasting)		3.3[10]	5.6[10]	mmol/L
		60[184]	100[184]	mg/dL
Random glucose		3.9[185]	7.8[185]	mmol/L
		70[186]	140[186]	mg/dL
Lactate (Venous)		4.5[30]	19.8[30]	mg/dL
		0.5[187]	2.2[187]	mmol/L
Lactate (Arterial)		4.5[30]	14.4[30]	mg/dL
		0.5[187]	1.6[187]	mmol/L
Pyruvate		300[30]	900[30]	μg/dL
		34[188]	102[188]	μmol/L
Ketones			1[189]	mg/dL
			0.1[189]	mmol/L

Medication

Test	Lower limit	Upper limit	Unit	Comments
Digoxin	0.5[190]	2.0[190]	ng/mL	Narrow therapeutic window
	0.6[190]	2.6[190]	nmol/L
Lithium	0.4,[191] 0.5,[192][193] 0.8[194]	1.3[192][193]	mmol/L	Narrow therapeutic window
Paracetamol		30[195]	mg/L	Risk of paracetamol toxicity at higher levels
		200[195]	μmol/L

See also

• Cardiology diagnostic tests and procedures
• Comprehensive metabolic panel
• Medical technologist
• Reference range

Notes

1. The MCHC in g/dL and the mass fraction of hemoglobin in red blood cells in % are numerically identical in practice, assuming a RBC density of 1g/mL and negligible hemoglobin in plasma.