Merck Manual

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Blood Tests: Normal Values

By

Osvaldo Padilla

, MD, MPH, Texas Tech Health Science Center;


Jude Abadie

, PhD, Texas Tech University Health Science Center

Reviewed/Revised Dec 2021 | Modified Sep 2022
View PATIENT EDUCATION
Topic Resources

Reference values vary based on several factors, including the specific laboratory that supplies them. A patient's blood test values should be interpreted based on the reference value of the laboratory in which the test was done; the laboratory typically provides these values with the test result. Representative values are listed in alphabetical order in the following table.

Table

Representative Laboratory Reference Values: Blood, Plasma, and Serum

Test

Specimen

Conventional Units

SI Units

Acetoacetate

Plasma

< 3 mg/L

< 0.3 mmol/L

Acetylcholinesterase (AChE), red blood cells

Blood

26.7–49.2 U/g Hb

1.72–3.17 x 106 U/mol Hb

Acid phosphatase (adults)

Serum

0.5–5 U/L

8–83 nkat/L

Activated partial thromboplastin time (aPTT)

Plasma

30–40 seconds

Adrenocorticotropic hormone (ACTH)

Serum

9–52 pg/mL (morning draw)

2–11 pmol/L (morning draw)

Albumin

Serum

3.5–5.4 g/dL

35–54 g/L

Aldosterone:

  • Standing

Serum

7–20 ng/dL

194–554 pmol/L

  • Supine

Serum

2–5 ng/dL

55–138 pmol/L

Alkaline phosphatase (ALP)

Serum

36–150 U/L

0.5–2.5 mckat/L

Alpha-1 antitrypsin (AAT)

Serum

100–273 mg/dL

18–50 mcmol/L

Alpha fetoprotein (AFP)

Serum

< 20 ng/mL

< 20 mcg/L

Aminolevulinic acid, Delta (ALA)

Serum

15–23 mcg/L

1.14–1.75 mcmol/L

Aminotransferase, alanine (ALT)

Serum

< 35 U/L

< 0.58 mckat/L

Aminotransferase, aspartate (AST)

Serum

< 35 U/L

< 0.58 mckat/L

Ammonia

Plasma

40–80 mcg/dL

23–47 mcmol/L

Amylase

Serum

< 110 U/L

< 1.8 mckat/L

Antibodies to extractable nuclear antigen (AENA)

Serum

< 20.0 units/mL

Anti–cyclic citrullinated peptide (anti-CCP) antibodies

Serum

≤ 20 units/mL

Antidiuretic hormone (ADH; arginine vasopressin)

Plasma

< 1.7 pg/mL

< 1.57 pmol/L

Anti–double-stranded DNA (dsDNA) antibodies, IgG

Serum

< 25 IU

Antimitochondrial M2 antibodies

Serum

< 0.1 units

Antineutrophil cytoplasmic antibodies (cANCA)

Serum

Negative

Antinuclear antibodies (ANA)

Serum

≤ 1.0 units

Anti–smooth muscle antibodies (ASMA) titer

Serum

≤ 1:80

Antistreptolysin O titer

Serum

< 150 units

Antithyroid microsomal antibody titer

Serum

< 1:100

+Antitrypsin, Alpha-1 (AAT)

Serum

83–199 mg/dL

15.3–36.6 mcmol/L

Apolipoproteins:

  • A-I, females

Serum

98–210 mg/dL

0.98–2.1 g/L

  • A-I, males

Serum

88–180 mg/dL

0.88–1.8 g/L

  • B-100, females

Serum

44–148 mg/dL

0.44–1.48 g/L

  • B-100, males

Serum

55–151 mg/dL

0.55–1.51 g/L

Bicarbonate

Serum

23–28 mEq/L

23–28 mmol/L

Bilirubin:

  • Direct

Serum

0–0.3 mg/dL

0–5.1 mcmol/L

  • Total

Serum

0.3–1.2 mg/dL

5.1–20.5 mcmol/L

Blood volumes (radioisotope labeling):

  • Plasma, females*

Blood

28–43 mL/kg body wt

0.028–0.043 L/kg body wt

  • Plasma, males*

Blood

25–44 mL/kg body wt

0.025–0.044 L/kg body wt

  • Red blood cells, females*

Blood

20–30 mL/kg body wt

0.02–0.03 L/kg body wt

  • Red blood cells, males*

Blood

25–35 mL/kg body wt

0.025–0.035 L/kg body wt

Brain (B-type) natriuretic peptide (BNP)

Plasma

< 100 pg/mL

< 100 ng/L

Calcitonin, age ≥ 16 years:

  • Females

Serum

< 8 pg/mL

< 8ng/L

  • Males

Serum

< 16 pg/mL

< 16 ng/L

Calcium

Serum

9–10.5 mg/dL

2.2–2.6 mmol/L

Cancer antigen (CA):

  • CA 125

Serum

< 35 U/mL

< 35 kU/L

  • CA 15-3

Serum

< 30 U/mL

< 30 kU/L

Carbon dioxide (CO2) content

Serum

23–28 mEq/L

23–28 mmol/L

Carbon dioxide partial pressure (PCO2)

Blood

Arterial: 35–45 mm Hg

Venous: 38–50 mm Hg

Arterial: 4.7–6.0 kPa

Venous: 5.1–6.7 kPa

Carboxyhemoglobin

Plasma

0.5–5%

Carcinoembryonic antigen (CEA)

Serum

< 3 ng/mL

Patients who smoke: < 5 ng/mL

< 3 mcg/L

Patients who smoke: < 5 mcg/L

Carotene

Serum

75–300 mcg/dL

1.4–5.6 mcmol/L

CD4:CD8 ratio

Blood

1.0–4.0

CD4+ T-cell count

Blood

640–1175/mcL

0.64–1.18 x 109/L

CD8+ T-cell count

Blood

335–875/mcL

0.34–0.88 x 109/L

Ceruloplasmin

Serum

14–40 mg/dL

0.93–2.65 mcmol/L

Chloride

Serum

98–106 mEq/L

98–106 mmol/L

Cholesterol, desirable level:

  • High-density lipoprotein (HDL-C)

Plasma

≥ 40 mg/dL

≥ 1.04 mmol/L

  • Low-density lipoprotein (LDL-C)

Plasma

≤ 130 mg/dL

≤ 3.36 mmol/L

Total (TC)

Plasma

150–199 mg/dL

3.88–5.15 mmol/L

Coagulation factors:

  • Factor I

Plasma

150–300 mg/dL

1.5–3.5 g/L

  • Factor II

Plasma

60–150% of normal

  • Factor IX

Plasma

60–150% of normal

  • Factor V

Plasma

60–150% of normal

  • Factor VII

Plasma

60–150% of normal

  • Factor VIII

Plasma

60–150% of normal

  • Factor X

Plasma

60–150% of normal

  • Factor XI

Plasma

60–150% of normal

  • Factor XII

Plasma

60–150% of normal

Complement:

  • C3

Serum

90–180 mg/dL

0.9–1.8 g/L

  • C4

Serum

10–40 mg/dL

0.10–0.40 g/L

Total (CH50)

Serum

30–75 U/mL

30–75 kU/L

Copper

Serum

70–155 mcg/dL

11–24.3 mcmol/L

Cortisol:

  • 1 hour after cosyntropin

Serum

> 18 mcg/dL and usually ≥ 8 mcg/dL above baseline

> 498 nmol/L and usually ≥ 221 nmol/L above baseline

  • At 5 PM

Serum

3–13 mcg/dL

83–359 nmol/L

  • At 8 AM

Serum

8–20 mcg/dL

251–552 nmol/L

  • After overnight suppression test

Serum

< 5 mcg/dL

< 138 nmol/L

C-peptide

Serum

0.9–4.3 ng/mL

297–1419 pmol/L

C-reactive protein (CRP)

Serum

< 0.8 mg/dL

< 8.0 mg/L

C-reactive protein, highly sensitive (hsCRP)

Serum

< 0.2 mg/dL

< 2.0 mg/L

Creatine kinase (CK)

Serum

30–170 U/L

0.5–2.83 mckat/L

Creatinine

Serum

Men: 0.7–1.2 mg/dL

Women: 0.5–1.0 mg/dL

Men: 60–110 mcmol/L

Women: 45–90 mcmol/L

D-dimer

Plasma

≤ 500 ng/mL FEU (Fibrinogen Equivalent Units)

< 3 nmol/L FEU

Dehydroepiandrosterone sulfate (DHEA-S):

  • Females

Plasma

0.6–3.3 mg/mL

1.6–8.9 mcmol/L

  • Males

Plasma

1.3–5.5 mg/mL

3.5–14.9 mcmol/L

Delta-aminolevulinic acid (ALA)

Serum

15–23 mcg/L

1.14–1.75 mcmol/L

11-Deoxycortisol (DOC):

  • After metyrapone

Plasma

> 7 mcg/dL

> 203 nmol/L

  • Basal

Plasma

< 5 mcg/dL

< 145 nmol/L

D-Xylose level 2 hours after ingestion of 25 g of D-xylose

Serum

> 20 mg/dL

> 1.3 nmol/L

Epinephrine, supine

Plasma

< 75 ng/L

< 410 pmol/L

Erythrocyte sedimentation rate (ESR):

  • Females

Blood

0–20 mm/hour

0–20 mm/hour

  • Males

Blood

0–15 mm/hour

0–20 mm/hour

Erythropoietin

Serum

2.6–18.5 mIU/mL

2.6–18.5 IU/L

Estradiol, females:

  • Day 1–10 of menstrual cycle

Serum

14–27 pg/mL

50–100 pmol/L

  • Day 11–20 of menstrual cycle

Serum

14–54 pg/mL

50–200 pmol/L

  • Day 21–30 of menstrual cycle

Serum

19–40 pg/mL

70–150 pmol/L

Estradiol, males

Serum

10–30 pg/mL

37–110 pmol/L

Ferritin:

  • Females

Serum

30–200 ng/mL

30–200 mcg/L

  • Males

Serum

30–300 ng/mL

30–300 mcg/L

Fetoprotein, Alpha (AFP)

Serum

< 8.4 ng/mL

< 8.4 mcg/L

Fibrinogen

Plasma

150–350 mg/dL

1.5–3.5 g/L

Folate (folic acid):

  • Red blood cells

Blood

160–855 ng/mL

362–1937 nmol/L

  • Serum

Serum

2.5–20 ng/mL

5.7–45.3 nmol/L

Follicle-stimulating hormone (FSH), females:

  • Follicular or luteal phase

Serum

5–20 mU/mL

5–20 U/L

  • Midcycle peak

Serum

30–50 mU/mL

30–50 U/L

  • Postmenopausal

Serum

> 35 mU/mL

> 35 U/L

Follicle-stimulating hormone (FSH), adult males

Serum

5–15 mU/mL

5–15 U/L

Fructosamine (glycated protein)

Plasma

200–285 mcmol/L

200-285 mcmol/L

Gamma-glutamyl transpeptidase (GGT)

Serum

Adult male: 8–61 U/L

Adult female: 5–36 U/L

Adult male: 0.14–1.03 mckat/L

Adult female:0.09–0.61 mckat/L

Gastrin

Serum

0–180 pg/mL

0–180 ng/L

Globulins:

Serum

2.5–3.5 g/dL

25–35 g/L

  • Alpha-1 globulins

Serum

0.2–0.4 g/dL

2–4 g/L

  • Alpha-2 globulins

Serum

0.5–0.9 g/dL

5–9 g/L

  • Beta globulins

Serum

0.6–1.1 g/dL

6–11 g/L

  • Beta-2 microglobulin

Serum

0.7–1.8 mcg/mL

0.7–1.8 mg/L

  • Gamma globulins

Serum

0.7–1.7 g/dL

7–17 g/L

Glucose:

  • 2-hour postprandial

Plasma

< 140 mg/dL

< 7.8 mmol/L

  • Fasting

Plasma

70–105 mg/dL

3.9–5.8 mmol/L

Glucose-6-phosphate dehydrogenase (G6PD)

Blood

5–15 U/g Hb

0.32–0.97 mU/ mol Hb

Glutamyl transpeptidase, Gamma (GGT)

Serum

Adult male: 8–61 U/L

Adult female: 5–36 U/L

Adult male: 0.14–1.03 mckat/L

Adult female: 0.09–0.61 mckat/L

Growth hormone:

  • After oral glucose

Plasma

< 2 ng/mL

< 2 mcg/L

  • In response to provocative stimuli

Plasma

> 7 ng/mL

> 7 mcg/L

Haptoglobin

Serum

30–200 mg/dL

0.3–2 g/L

Hematocrit:

  • Females

Blood

36–47%

  • Males

Blood

41–51%

Hemoglobin:

  • Females

Blood

12–16 g/dL

120–160 g/L

  • Males

Blood

14–17 g/dL

140–170 g/L

Hemoglobin A1C

Blood

4.7–8.5%

Hemoglobin electrophoresis, adults:

  • Hb A1

Blood

95–98%

  • Hb A2

Blood

2–3%

  • Hb C

Blood

0%

  • Hb F

Blood

0.8–2.0%

  • Hb S

Blood

0%

Hemoglobin electrophoresis, Hb F in children:

  • Neonate

Blood

50–80%

  • 1–6 months

Blood

8%

  • > 6 months

Blood

1–2%

Homocysteine:

  • Females

Plasma

0.40–1.89 mg/L

3–14 mcmol/L

  • Males

Plasma

0.54–2.16 mg/L

4–16 mcmol/L

Human chorionic gonadotropin (hCG), quantitative

Serum

< 5 mIU/mL

< 5 IU/L

Immunoglobulins:

  • IgA

Serum

70–300 mg/dL

0.7–3.0 g/L

  • IgD

Serum

< 8 mg/dL

< 80 mg/L

  • IgE

Serum

0.01–0.04 mg/dL

0.1–0.4 mg/L

  • IgG

Serum

640–1430 mg/dL

6.4–14.3 g/L

  • IgG1

Serum

280–1020 mg/dL

2.8–10.2 g/L

  • IgG2

Serum

60–790 mg/dL

0.6–7.9 g/L

  • IgG3

Serum

14–240 mg/dL

0.14–2.4 g/L

  • IgG4

Serum

11–330 mg/dL

0.11–3.3 g/L

  • IgM

Serum

20–140 mg/dL

0.2–1.4 g/L

Insulin, fasting

Serum

2.6–24.9 mcIU/mL

15.6–149.4 pmol/L

International normalized ratio (INR):

  • Therapeutic range (standard intensity therapy)

Plasma

2.0–3.0

  • Therapeutic range in higher risk patients (eg, those with prosthetic heart valves)

Plasma

2.5–3.5

  • Therapeutic range in patients with lupus anticoagulant

Plasma

3.0–3.5

Iron

Serum

Males: 50–150 mcg/dL

Females: 35–145 mcg/dL

Males: 9.2–27.5 mcmol/L

Females: 6.4–26.5 mcmol/L

Iron-binding capacity, total (TIBC)

Serum

250–460 mcg/dL

45–82 mcmol/L

Lactate dehydrogenase (LDH)

Serum

60–160 U/L

1–1.67 mckat/L

Lactic acid, venous

Blood

6–16 mg/dL

0.67–1.8 mmol/L

Lactose tolerance test

Plasma

> 15 mg/dL increase in plasma glucose level

> 0.83 mmol/L increase in plasma glucose level

Lead

Blood

Pediatric patients: < 20 mcg/dL

Adult patients: < 80 mcg/dL

Pediatric patients: < 0.97 mcmol/L

Adult patients: < 3.86 mcmol/L

Leukocyte alkaline phosphatase (LAP) score

Peripheral blood smear

13–130/100/ polymorphonuclear (PMN) leukocyte neutrophils and bands

Lipase

Serum

< 95 U/L

< 1.58 mckat/L

Lipoprotein (a) [Lp(a)]

Serum

≤ 10 mg/dL

< 13nmol/L

Luteinizing hormone (LH), females:

  • Follicular or luteal phase

Serum

5–22 mU/mL

5–22 U/L

  • Midcycle peak

Serum

30–250 mU/mL

30–250 U/L

  • Postmenopausal

Serum

> 30 mU/mL

> 30 U/L

Luteinizing hormone, males

Serum

3–15 mU/mL

3–15 U/L

Magnesium

Serum

1.5–2.4 mg/dL

0.62–0.99 mmol/L

Manganese

Serum

0.3–0.9 ng/mL

5.5–16.4 nmol/L

Mean corpuscular hemoglobin (MCH)

Blood

28–32 pg

Mean corpuscular hemoglobin concentration (MCHC)

Blood

32–36 g/dL

320–360 g/L

Mean corpuscular volume (MCV)

Blood

80–100 fL

Metanephrines, fractionated:

  • Metanephrines, free

Plasma

< 0.50 nmol/L

  • Normetanephrines, free

Plasma

< 0.90 nmol/L

Methemoglobin

Blood

< 1.0%

Methylmalonic acid (MMA)

Serum

≤ 400 nmol/L

47.2 ng/L

Myoglobin:

  • Females

Serum

25–58 mcg/L

1.4–3.5 nmol/L

  • Males

Serum

28–72 mcg/L

1.6–4.1 nmol/L

Norepinephrine, supine

Plasma

50–440 pg/mL

0.3–2.6 nmol/L

N-Terminal propeptide of BNP (NT-proBNP)

Plasma

< 75 years: < 125 pg/mL

≥ 75 years: < 450 pg/mL

< 125 ng/L

< 450 ng/L

5'-Nucleotidase (5'NT)

Serum

4–11.5 U/L

Osmolality

Plasma

275–295 mOsm/kg H2O

275–295 mmol/ kg H2O

Osmotic fragility test

Blood

Increased fragility if hemolysis occurs in > 0.5% sodium chloride

Decreased fragility if hemolysis is incomplete in 0.3% sodium chloride

Oxygen partial pressure (PO2)

Blood

Arterial: 80–100 mm Hg

10.7–13.3 kPa

Parathyroid hormone (PTH)

Serum

10–65 pg/mL

10–65 ng/L

Parathyroid hormone–related peptide (PTHrP)

Plasma

< 2.0 pmol/L

Partial thromboplastin time, activated (aPTT)

Plasma

25–35 seconds

pH

Blood

Arterial: 7.35–7.45

Venous: 7.32–7.43

Phosphorus, inorganic

Serum

3.0–4.5 mg/dL

0.97–1.45 mmol/L

Platelet count

Blood

150–350 x 103/mcL

150–350 x 109/L

Platelet life span, using chromium-51 (51Cr)

8–12 days

Porphyrins

Plasma

≤ 1.0 mcg/dL

≤ 10 mcg/L

Potassium

Serum

3.5–5 mEq/L

3.5–5 mmol/L

Prealbumin (transthyretin)

Serum

18–45 mg/dL

180–450 mg/L

Progesterone:

  • Follicular phase

Serum

< 1 ng/mL

< 0.03 nmol/L

  • Luteal phase

Serum

3–30 ng/mL

0.1–0.95 nmol/L

Prolactin:

  • Females (nonpregnant)

Serum

< 20 mcg/L

< 870 pmol/L

  • Males

Serum

< 15 mcg/L

< 652 pmol/L

Prostate-specific antigen, total (PSA-T)

Serum

0–4 ng/mL

0–4 mcg/L

Prostate-specific antigen, ratio of free to total (PSA-F:PSA-T)

Serum

> 0.25

Protein C activity

Plasma

67–131%

Protein C resistance, activated ratio (APC-R)

Plasma

2.2–2.6

Protein S activity

Plasma

82–144%

Protein, total

Serum

6–7.8 g/dL

60–78 g/L

Prothrombin time (PT)

Plasma

11–13 seconds

Pyruvic acid

Blood

0.08–0.16 mmol/L

Red blood cell count

Blood

4.2–5.9 x 106 cells/mcL

4.2–5.9 x 1012 cells/L

Red blood cell survival rate, using 51Cr

Blood

T1/2 = 28 days

Renin activity, plasma (PRA), upright, in males and females aged 18–39 years:

  • Sodium-depleted

Plasma

2.9–24 ng/mL/hour

2.9–24 mcg/L/hour

  • Sodium-repleted

Plasma

0.6 (or lower)–4.3 ng/mL/hour

0.6 (or lower)–4.3 mcg/L/hour

Reticulocyte count:

  • Percentage

Blood

0.5–1.5%

  • Absolute

Blood

23–90 x 103/mcL

23–90 x 109/L

Rheumatoid factor (RF), by nephelometry

Serum

< 20 IU/mL

< 20 kIU/L

Sodium

Serum

136–145 mEq/L

136–145 mmol/L

Testosterone (total), adults:

  • Females

Serum

20–75 ng/dL

0.7–2.6 nmol/L

  • Males

Serum

300–1200 ng/dL

10–42 nmol/L

Thrombin time

Plasma

18.5–24 seconds

Thyroid iodine-123 (123I) uptake

5–30% of administered dose at 24 hour

Thyroid-stimulating hormone (TSH)

Serum

0.5–5.0 mcIU/mL

0.5–5.0 mIU/L

Thyroxine (T4):

  • Free

Serum

0.9–2.4 ng/dL

12–31 pmol/L

  • Free index

4–11

  • Total

Serum

5–12 mcg/dL

64–155 nmol/L

Transferrin

Serum

200–360 mg/dL

2.0–3.6 g/L

Transferrin saturation

Serum

20–50%

Triglycerides (fasting)

Serum

Normal: < 150 mg/dL

Borderline: 150–199 mg/dL

High: 200–499 mg/dL

Very high: ≥ 500 mg/dL

Normal: < 1.69 mmol/L

Borderline: 1.69–2.25 mmol/L

High: 2.26–5.64 mmol/L

Very high: > 5.65 mmol/L

Triiodothyronine (T3):

  • Uptake

Serum

25–35%

  • Total

Serum

70–195 ng/dL

1.1–3.0 nmol/L

Troponin I (Contemporary assay)

Plasma

< 0.04 ng/mL

< 0.04 mcg/L

Troponin I, highly sensitive (hs-TnI)

Serum

Females: ≤ 10 ng/L

Males: ≤ 15 ng/L

<1.0>

<1.5>

Troponin T (Contemporary assay)

Serum

≤ 0.03 ng/mL

≤ 0.03 mcg/L

Troponin T, highly sensitive (hs-TnT)

Serum

Females: ≤ 10 ng/L

Males: ≤ 15 ng/L

<1.0>

<1.5>

Urea nitrogen (BUN)

Serum

8–20 mg/dL

2.9–7.1 mmol/L

Uric acid

Serum

2.5–8 mg/dL

0.15–0.47 mmol/L

Vitamin B12

Serum

200–800 pg/mL

148–590 pmol/L

Vitamin C (ascorbic acid):

  • Leukocyte

Blood

< 20 mg/dL

< 1136 mcmol/L

  • Total

Blood

0.4–1.5 mg/dL

23–85 mcmol/L

Vitamin D:

  • 1,25-Dihydroxycholecalciferol (calcitriol)

Serum

25–65 pg/mL

65–169 pmol/L

  • 25-Hydroxycholecalciferol

Serum

15–80 ng/mL

37–200 nmol/L

White blood cell count

Blood

4.5–11 x 103 cells/mcL

4.5–11 x 109 cells/L

Segmented neutrophils

2.6–8.5 x 103 cells/mcL

2.6–8.5 x 109 cells/L

Band neutrophils

0–1.2 x 103 cells/mcL

0–1.2 x 109 cells/L

Lymphocytes

0.77–4.5 x 103 cells/mcL

0.77–4.5 x 109 cells/L

Monocytes

0.14–1.3 x 103 cells/mcL

0.14–1.3 x 109 cells/L

Eosinophils

0–0.55 x 103 cells/mcL

0–0.55 x 109 cells/L

Basophils

0–0.22 x 103 cells/mcL

0–0.22 x 109 cells/L

Zinc

Serum

66–110 mcg/dL

10.1–16.8 mcmol/L

*American Board of Internal Medicine: ABIM Laboratory Test Reference Ranges ̶ July 2021. Accessed 9/16/2021.

mckat = microkatal; pkat = picokatal.

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