Archive for the ‘USMLE’ Category

For Medical Students: Normal values for laboratory investigations, BP, and BMI (USMLE-friendly)

“We teach our students that they should not believe us… Do not believe your professors!” Dr. Kevin Hanretty, University of Glasgow, UK.

If some professors, somewhere, are teaching their students not to trust them, how come that you trust a colleague of yours? Therefore, the  source of the below information: Unless specified, most of the values are from “Step 1: Content Description & General Information 2012”, p. 22,  The remaining few are from “Reference Intervals for Laboratory Tests & Procedures”, ch.708, Nelson Textbook of Pediatrics, 19th ed, 2011.

*** To view and download a printer-friendly version, you can visit Google Docs at: ***

Normal Values: Laboratory, BP, and BMI
Reference Range
Conventional Units SI Units
Serum Nonelectrolytes
Amylase, serum 25-125 U/L
Phosphatase (alkaline), serum (p-NPP at 30EC) 20-70 U/L
Alanine aminotransferase (ALT at 30EC) SGPT(serum glutamic-pyruvic transaminase) 8-20 U/L
Aspartate aminotransferase (AST at 30EC) SGOT(serum glutamic-oxaloacetic transaminase) 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL 2-17 µmol/L // 0-5 µmol/L
Lipoprotein levels – Adult Treatment Panel (ATP) III Classification of LDL, Total, and HDL Cholesterol (mg/dL):Cholesterol mmol/L (Total, LDL, and HDL) = mg/dL ÷ 38.6 // Triglyceride mmol/L = mg/dL ÷ 88.5 LDL Cholesterol (Primarytarget of therapy):

  • <100: Optimal
  • 100-129: Near optimal/above optimal
  • 130-159: Borderline high
  • 160-189: High
  • ≥190: Very high

Serum Triglycerides:

  • <150: Normal
  • 150-199: Borderline high
  • 200-499: High
  • ≥500: Very high
Total Cholesterol:

  • <200: Desirable\Recommen.
  • 200-239: Borderline high
  • ≥240: High

HDL Cholesterol:

  • <40: Low
  • ≥60: High
Creatine kinase, serum M: 25-90 U/L // F: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL 53-106 µmol/L
Urea nitrogen, serum Cord blood: 21-40 // Premature (1 wk): 3-25 // Newborn: 3-12 // Infant or child: 5-18 // Thereafter: 7-18 mg/dL Thereafter: 2.5-6.4 mmol/L [BUN (mmol/L) = BUN (mg/d)/2.8]
Uric acid, serum 3.0-8.2 mg/dL 0.18-0.48 mmol/L
Glucose, serum Fasting: 70-99 mg/dL (USMLE: 110 mg/dL) (3.8-5.6) mmol/L2-h postprandial: < 120 mg/dL (6.6 mmol/L)
Categories of increased risk for diabetes (prediabetes): FPG: 100-125 mg/dL (5.6-6.9 mmol/L): IFG OR 2-h plasma glucose in the 75-g OGTT: 140-199 mg/dL (7.8-11.0 mmol/L): IGT OR A1C: 5.7-6.4%
Diabetes can be diagnosed with either one of the following four criteria:
(Source: Standards of Medical Care in Diabetes 2011, American Diabetes Association)  Glucose (mmol) = Glucose (mg/dL)/18
1. A1C ≥ 6.5%.The test should be performed in a laboratory using a method that is NGSP certified and standardized to the DCCT assay. *2. FPG ≥ 126 mg/dL (7.0 mmol/L).Fasting is defined as no caloric intake for at least 8 h.*3. 2-h plasma glucose ≥ 200 mg/dL (11.1 mmol/L) during an OGTT.The test should be performed as described by the World Health Organization, using a glucose load containing the equivalent of 75 g anhydrous glucose dissolved in water.*4. In a patient with classic symptoms of hyperglycemia or hyperglycemic crisis, a random plasma glucose ≥ 200 mg/dL (11.1 mmol/L)*(*In the absence of unequivocal hyperglycemia, result should be confirmed by repeat testing.)
Lactate dehydrogenase, serum 45-90 U/L
Osmolality, serum 275-295 mOsmol/kg (Osmolality=  2x[Na] + [Glucose]/18 + [BUN]/2.8)
Iron 50-170 µg/dL 9-30 µmol/L
Ferritin, serum M: 15-200 ng/mL
F: 12-150 ng/mL
M: 15-200 µg/L 
 12-150 µg/L
Serum proteins Total (recumbent) 6.0-7.8 g/dL 60-78 g/L
Albumin 3.5-5.5 g/dL 35-55 g/L
Globulin 2.3-3.5 g/dL 23-35 g/L
Immunoglobulins, serum IgAIgE
76-390 mg/dL0-380 IU/mL650-1500 mg/dL40-345 mg/dL 0.76-3.90 g/L0-380 kIU/L6.5-15 g/L0.4-3.45 g/L
Serum hormones
Cortisol, serum 0800 h: 5-23 µg/dL
1600 h: 3-15 µg/dL
2000 h: <50% of 0800 h
138-635 nmol/L
82-413 nmol/L
Fraction of 0800 h: <0.50
TSH, serum or plasma 0.5-5.0 µU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24 h 0.08-0.30/24 h
Thyroxine (T4), serum 5-12 µg/dL 64-155 nmol/L
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL 1.8-2.9 nmol/L
Triiodothyronine (T3) resin uptake 25%-35% 0.25-0.35
LH, serum/plasma
(Range in SI units: Same but in U/L)
M: 6-23 mIU/mL // F: follicular phase 5-30 mIU/mL // midcycle 75-150 mIU/mL // postmenopause 30-200 mIU/mL
PTH, serum, N-terminal 230-630 pg/mL (Pico=10-12 230-630 ng/L (Nano=10-9)
Prolactin, serum (hPRL) <20 ng/mL <20 µg/L
Estriol, total, serum (in pregnancy) 24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL 104-590 nmol/L // 208-970 nmol/L
28-32 wks // 36-40 wks 40-220 ng/mL // 80-350 ng/mL 140-760 nmol/L // 280-1210 nmol/L
FSH, serum/plasma
(Range in SI units: Same but in U/L)
M: 4-25 mIU/mL // F: premenopause 4-30 mIU/mL// midcycle peak 10-90 mIU/mL // postmenopause 40-250 mIU/mL
GH  – arginine stimulation
(Range in SI units: Same but in ug/L)
Fasting: <5 ng/mL // Provocative stimuli: >7 ng/mL
Serum Electrolytes
  1. 1.  Sodium (Na+)
  2. 2.  Potassium (K+)
  3. 3.  Chloride (Cl)
  4. 4.  Calcium, serum (Ca2+)
  5. 5.  Magnesium (Mg2+)
  6. 6.  Bicarbonate (HCO3)
  7. 7.  Phosphorus (inorganic), serum
136-145 mEq/L3.5-5.0 mEq/L95-105 mEq/L8.4-10.2 mg/dL1.5-2.0 mEq/L22-28 (25 ± 3) mEq/L3.0-4.5 mg/dL 136-145 mmol/L3.5-5.0 mmol/L95-105 mmol/L2.1-2.8 mmol/L0.75-1.0 mmol/L22-28 (25 ± 3)  mmol/L1.0-1.5 mmol/L
Arterial Blood Gases (ABGs) (room air)
pHPaCO2 PaO2 7.35-7.45 (7.40 ± 0.05)35-45 (40 ± 5) mm Hg75-105 mm Hg [H+] = 36-44 nmol/L4.7-5.9 kPa10.0-14.0 kPa
Erythrocyte count M: 4.3-5.9 million/mm3F: 3.5-5.5 million/mm3 M: 4.3-5.9 x 1012/LF: 3.5-5.5 x 1012/L
ESR (Westergren method) (mm/hr) (Source: Medscape) NB: 0-2 // NB to puberty: 3-13  // M under 50: < 15 // F under 50: < 20 // M over 50: < 20 // F over 50: < 30
Hematocrit or PCV (Packed red cell volume) M: 41%-53%
F: 36%-46%
M: 0.41-0.53
F: 0.36-0.46
Hemoglobin, blood  0-30 days:15.0-24.0 g/dL1-23 mo: 10.5-14.0 g/dL
Until 18:11.5-16.1 (M) // 15.0 (F)…M:13.5-17.5 g/dLF: 12.0-16.0 g/dL
0-30 days:2.32-3.72 mmol/L1-23 mo:1.63-2.17 mmol/LUntil 18: 1.78-2.50 (M) // 2.32 (F)
M:2.09-2.71 mmol/LF: 1.86-2.48 mmol/L
Hemoglobin, plasma 1-4 mg/dL 0.16-0.62 mmol/L
Reticulocyte count 0.5%-1.5% of red cells 0.005-0.015
MCH 25.4-34.6 pg/cell 0.39-0.54 fmol/cell
MCHC 31%-36% Hb/cell 4.81-5.58 mmol Hb/L
MCV 80-100 µm3 80-100 fL (Femto  =10-15)
RDW_CV (Coefficient of Variation) 11.6-14.6% in adult
RDW_SD (Standard Deviation) 39-46 fL
Platelet count 150,000-400,000/mm3 150-400 x 109/L
Partial thromboplastin time (activated) 25-40 s
Prothrombin time 11-15 s
INR 1.0-1.1
Bleeding time (template) 2-7 minutes
Thrombin time <2s deviation from control
Leukocyte count and differential
Leukocyte count (WCC: White Cell Count) 4,500-11,000/mm3 4.5-11.0 x 109/L
  1. 1.    Segmented neutrophils
  2. 2.    Lymphocytes
  3. 3.    Monocytes
  4. 4.    Eosinophils
  5. 5.    Basophils
  6. 6.    Bands
54%-62%25%-33%3%-7%1%-3%0%-0.75%3%-5% 0.54-0.620.25-0.330.03-0.070.01-0.030-0.00750.03-0.05
Volume    Plasma M: 25-43 mL/kg
F: 28-45 mL/kg
M: 0.025-0.043 L/kg
F: 0.028-0.045 L/kg
   Red cell M:20-36 mL/kgF: 19-31 mL/kg M: 0.020-0.036 L/kg
F: 0.019-0.031 L/kg
Chloride 0-35 mmol/L (ñ in CF, Ald defeciency, or pseudohypoaldosteronism)
Sodium 5-40 mmol/L
Oxalate 8-40 µg/mL 90-445 µmol/L
Proteins, total < 150 mg/24 h <0.15 g/24 h
Calcium 100-300 mg/24 h 2.5-7.5 mmol/24 h
Osmolality 50-1400 mOsmol/kg
Sodium, potassium, chloride, and uric acid Vary with intake/diet
Creatinine clearance M: 97-137 mL/min // F: 88-128 mL/min
Estriol, total (in pregnancy):

  • 30 wks
  • 35 wks
  • 40 wks
6-18 mg/24 h9-28 mg/24 h13-42 mg/24 h 21-62 µmol/24 h31-97 µmol/24 h45-146 µmol/24 h
17-Hydroxycorticosteroids M:3.0-10.0 mg/24 hF: 2.0-8.0 mg/24 h 8.2-27.6 µmol/24 h5.5-22.0 µmol/24 h
17-Ketosteroids, total M:8-20 mg/24 hF: 6-15 mg/24 h 28-70 µmol/24 h21-52 µmol/24 h
Urinary dipstick test (mg/dL) Trace: 10-20 // 1+: 30  // 2+: 100 // 3+: 300 // 4+: 1,000-2,000
Cell count 0-5 cells/mm3 0-5 x 106/L
Chloride 118-132 mEq/L 118-132 mmol/L
Gamma globulin 3-12% total proteins 0.03-0.12
Glucose 40-70 mg/dL 2.2-3.9 mmol/L
Proteins, total < 40 mg/dL < 0.40 g/L
Pressure 70-180 mm H2O
BP Classification (Source: Seventh report of the JNC, 2003, American Heart Association)
SBP (mm Hg) DBP (mm Hg)
Normal <120 and <80
Prehypertension 120–139 or 80–89
Stage 1 Hypertension 140–159 or 90–99
Stage 2  Hypertension ≥160 or ≥100
Body Mass Index (BMI)  (kg/m2(Source: WHO)
Underweight: <18.5 // Normal: 18.5-24.99 // Overweight: 25-29.99 // Obese: ≥ 30 (BMI =  Weight (kg) / Height(m)2)
  • 1 m3 = 103 dm3 = 106 cc = 10mm3 (One cubic meter = One thousand cubic decimeter = One million cubic cm =  One billion cubic mm = one billion uL)
  • 1 L = 1,000 cc = 1,000,000 mm3 = 1,000,000 uL // 1 uL = 1 mm3

 By: Hijazeen, JK. Any feedback? 

USMLE step 2 cs: New patient note

I am subscribed a newsletter by the ECFMG. Once subscribed to this mailing list, you get the most updated information regarding the USMLE. On december the 20th, 2011, I received an email from them annoucing “CHANGES TO THE STEP 2 CLINICAL SKILLS (CS) EXAMINATION”.

The next important question after asking what are the changes is “when are they going to take place”. “These changes will be introduced in Step 2 CS for examinations delivered beginning June 17, 2012.”


I like the new changes they are making to the patient note.

“In the new note, examinees will continue to be asked to document relevant history and physical examination findings and to list initial diagnostic studies to be ordered. Examinees will also be asked to create a reasoned, focused differential (maximum of three diagnoses) listed in order of likelihood and to indicate the evidence obtained from the history and physical examination that supports (or refutes) each potential diagnosis. The new patient note provides examinees with an opportunity to document their analysis of a patient’s possible diagnoses.”

Take a look at the new CS patient note:



For those who were not registered in the ECFMG mailing list, here is their full email:


The ECFMG(r) Reporter
An E-Newsletter for International Medical Graduates Pursuing Graduate Medical Education in the United States
Issue 180 – December 20, 2011
One of the recommendations emerging from the Comprehensive Review of USMLE (CRU) process is that USMLE consider ways to further enhance the testing methods used in the Step 2 Clinical Skills (CS) examination. As previously announced in the 2012 Bulletin of Information, these enhancements are scheduled for implementation in mid-2012. These changes will be introduced in Step 2 CS for examinations delivered beginning June 17, 2012.
The reporting schedule for examinees testing from June 17, 2012 through November 3, 2012 will be 2-3 weeks longer than for examinees testing during other periods.
More information about the Step 2 CS score reporting dates for examinations delivered in 2012 is provided in the Step 2 CS Score Reporting Schedule at
The CIS subcomponent of Step 2 CS has been redesigned to assess a fuller range of competencies.  Background information about these changes is provided on pages 5-6 of the Fall 2010/Winter 2011 NBME Examiner at The new approach divides communication skills into a series of functions. These functions have been further divided into sub-functions. Beginning June 17, 2012, the Communication and Interpersonal Skills (CIS) scale will focus on five functions:
1.      Fostering the relationship
2.      Gathering information
3.      Providing information
4.      Making decisions: basic
5.      Supporting emotions: basic
Several additional functions are still under development; these include making decisions: advanced; supporting emotions: advanced; and helping patients with behavior change. A list of the functions and sub-functions is available at
Also beginning June 17, 2012, a new patient note will be introduced. The patient note is completed by the Step 2 CS examinee after the encounter with the standardized patient. In the new note, examinees will continue to be asked to document relevant history and physical examination findings and to list initial diagnostic studies to be ordered. Examinees will also be asked to create a reasoned, focused differential (maximum of three diagnoses) listed in order of likelihood and to indicate the evidence obtained from the history and physical examination that supports (or refutes) each potential diagnosis. The new patient note provides examinees with an opportunity to document their analysis of a patient’s possible diagnoses. A sample of the new patient note is available for review at
Updated practice materials for Step 2 CS will be posted to the USMLE website in March 2012. These include the Step 2 CS Content Description and General Information Booklet, onsite orientation video, sample patient notes, and a simulation of the program for typing patient notes.
As an organization, ECFMG is committed to providing information on issues of importance to international medical graduates. We realize that many individuals would like updated information on developing issues related to ECFMG Certification and entry into graduate medical education in the United States. As a result, ECFMG has developed The ECFMG(r) Reporter to provide international medical graduates worldwide with timely, objective information on current topics of interest. It is our hope that this newsletter will allow physicians educated outside the United States and Canada to make informed choices on issues that shape their careers.
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