Medical Terminology and Coding Standards
Standard Nomenclature Systems
SNOMED CT (Systematized Nomenclature of Medicine - Clinical Terms)
Purpose: Comprehensive clinical terminology for electronic health records
Coverage:
- Clinical findings
- Symptoms
- Diagnoses
- Procedures
- Body structures
- Organisms
- Substances
- Pharmaceutical products
- Specimens
Structure:
- Concepts with unique identifiers
- Descriptions (preferred and synonyms)
- Relationships between concepts
- Hierarchical organization
Example:
- Concept: Myocardial infarction
- SNOMED CT code: 22298006
- Parent: Heart disease
- Children: Acute myocardial infarction, Old myocardial infarction
Benefits:
- Enables semantic interoperability
- Supports clinical decision support
- Facilitates data analytics
- International standard
LOINC (Logical Observation Identifiers Names and Codes)
Purpose: Universal code system for laboratory and clinical observations
Components of LOINC code:
- Component (analyte or measurement): What is measured
- Property: What characteristic (mass, volume, etc.)
- Timing: When measured (point in time, 24-hour)
- System: Specimen or system (serum, urine, arterial blood)
- Scale: Type of result (quantitative, ordinal, nominal)
- Method: How measured (when relevant to interpretation)
Examples:
LOINC Parts:
- Document types
- Survey instruments
- Clinical attachments
- Radiology codes
- Pathology codes
ICD-10-CM (International Classification of Diseases, 10th Revision, Clinical Modification)
Purpose: Diagnosis and procedure coding for billing, epidemiology, and health statistics
Structure:
- Alphanumeric codes (3-7 characters)
- First character: letter (except U)
- Characters 2-3: numbers
- Characters 4-7: alphanumeric (decimal after 3rd character)
- Laterality, severity, encounter type specified
Code structure example:
- S72.001A: Fracture of unspecified part of neck of right femur, initial encounter
- S: Injury category
- 72: Femur
- 001: Unspecified part of neck
- A: Initial encounter for closed fracture
- Right side indicated by 1 in 5th position
Common categories:
- A00-B99: Infectious diseases
- C00-D49: Neoplasms
- E00-E89: Endocrine, nutritional, metabolic
- F01-F99: Mental and behavioral
- G00-G99: Nervous system
- I00-I99: Circulatory system
- J00-J99: Respiratory system
- K00-K95: Digestive system
- M00-M99: Musculoskeletal
- N00-N99: Genitourinary
- S00-T88: Injury, poisoning
Seventh character extensions:
- A: Initial encounter
- D: Subsequent encounter
- S: Sequela
Placeholder X:
- Used when code requires 7th character but fewer than 6 characters
- Example: T36.0X5A (Adverse effect of penicillins, initial encounter)
Combination codes:
- Single code describing two diagnoses or diagnosis with manifestation
- Example: E11.21 (Type 2 diabetes with diabetic nephropathy)
CPT (Current Procedural Terminology)
Purpose: Procedure and service coding for billing
Maintained by: American Medical Association (AMA)
Categories:
- Category I: Procedures and services (5-digit numeric codes)
- Category II: Performance measurement (4 digits + F)
- Category III: Emerging technology (4 digits + T)
Category I Sections:
- 00100-01999: Anesthesia
- 10000-69990: Surgery
- 70000-79999: Radiology
- 80000-89999: Pathology and Laboratory
- 90000-99999: Medicine
- 99000-99607: Evaluation and Management (E/M)
E/M Codes (commonly used):
- 99201-99215: Office visits (new and established)
- 99221-99239: Hospital inpatient services
- 99281-99285: Emergency department visits
- 99291-99292: Critical care
- 99304-99318: Nursing facility services
Modifiers:
- Two-digit codes appended to CPT codes
- Indicate service was altered but not changed
- Examples:
- -25: Significant, separately identifiable E/M service
- -50: Bilateral procedure
- -59: Distinct procedural service
- -76: Repeat procedure by same physician
- -RT/LT: Right/Left side
RxNorm
Purpose: Normalized names for clinical drugs and drug delivery devices
Structure:
- Includes brand and generic names
- Dose forms
- Strengths
- Links to other drug vocabularies (NDC, SNOMED CT)
Example:
- Concept: Amoxicillin 500 MG Oral Capsule
- RxNorm CUI: 308191
- Ingredients: Amoxicillin
- Strength: 500 MG
- Dose Form: Oral Capsule
Medical Abbreviations
Acceptable Standard Abbreviations
Time:
- q: every (q4h = every 4 hours)
- qd: daily (avoid - use "daily")
- bid: twice daily
- tid: three times daily
- qid: four times daily
- qhs: at bedtime
- prn: as needed
- ac: before meals
- pc: after meals
- hs: at bedtime
Routes:
- PO: by mouth (per os)
- IV: intravenous
- IM: intramuscular
- SC/SQ/subcut: subcutaneous
- SL: sublingual
- PR: per rectum
- NG: nasogastric
- GT: gastrostomy tube
- TD: transdermal
- inh: inhaled
Frequency:
- stat: immediately
- now: immediately
- continuous: without interruption
- PRN: as needed
Laboratory:
- CBC: complete blood count
- BMP: basic metabolic panel
- CMP: comprehensive metabolic panel
- LFTs: liver function tests
- PT/INR: prothrombin time/international normalized ratio
- PTT/aPTT: partial thromboplastin time/activated PTT
- ESR: erythrocyte sedimentation rate
- CRP: C-reactive protein
- ABG: arterial blood gas
- UA: urinalysis
- HbA1c: hemoglobin A1c
Diagnoses:
- HTN: hypertension
- DM: diabetes mellitus
- CHF: congestive heart failure
- CAD: coronary artery disease
- COPD: chronic obstructive pulmonary disease
- CVA: cerebrovascular accident
- MI: myocardial infarction
- PE: pulmonary embolism
- DVT: deep vein thrombosis
- UTI: urinary tract infection
- CKD: chronic kidney disease
- ESRD: end-stage renal disease
Physical Examination:
- HEENT: head, eyes, ears, nose, throat
- PERRLA: pupils equal, round, reactive to light and accommodation
- EOMI: extraocular movements intact
- JVP: jugular venous pressure
- RRR: regular rate and rhythm
- CTAB: clear to auscultation bilaterally
- BS: bowel sounds or breath sounds (context dependent)
- NT/ND: non-tender, non-distended
- FROM: full range of motion
Vital Signs:
- BP: blood pressure
- HR: heart rate
- RR: respiratory rate
- T or Temp: temperature
- SpO2: oxygen saturation
- Wt: weight
- Ht: height
- BMI: body mass index
Do Not Use Abbreviations (Joint Commission)
Prohibited abbreviations:
| Abbreviation |
Intended Meaning |
Problem |
Use Instead |
| U |
Unit |
Mistaken for 0, 4, or cc |
Write "unit" |
| IU |
International Unit |
Mistaken for IV or 10 |
Write "international unit" |
| Q.D., QD, q.d., qd |
Daily |
Mistaken for each other |
Write "daily" |
| Q.O.D., QOD, q.o.d., qod |
Every other day |
Mistaken for QD or QID |
Write "every other day" |
| Trailing zero (X.0 mg) |
X mg |
Decimal point missed |
Never write zero after decimal (write X mg) |
| Lack of leading zero (.X mg) |
0.X mg |
Decimal point missed |
Always write zero before decimal (write 0.X mg) |
| MS, MSO4, MgSO4 |
Morphine sulfate or magnesium sulfate |
Confused for each other |
Write "morphine sulfate" or "magnesium sulfate" |
Additional problematic abbreviations:
- µg: micrograms (mistaken for mg) → write "mcg"
- cc: cubic centimeters → write "mL"
- hs: half-strength or hour of sleep → write "half-strength" or "bedtime"
- TIW: three times a week → write "three times weekly"
- SC, SQ: subcutaneous → write "subcut" or "subcutaneous"
- D/C: discharge or discontinue → write full word
- AS, AD, AU: left ear, right ear, both ears → write "left ear," "right ear," "both ears"
- OS, OD, OU: left eye, right eye, both eyes → write "left eye," "right eye," "both eyes"
Medication Nomenclature
Generic vs. Brand Names
Best practice: Use generic names in medical documentation
Examples:
- Acetaminophen (generic) vs. Tylenol (brand)
- Ibuprofen (generic) vs. Advil, Motrin (brand)
- Atorvastatin (generic) vs. Lipitor (brand)
- Metformin (generic) vs. Glucophage (brand)
- Lisinopril (generic) vs. Zestril, Prinivil (brand)
When to include brand:
- Patient education (recognition)
- Novel drugs without generic
- Narrow therapeutic index drugs with bioequivalence issues
- Biologic products
Dosage Forms
Solid oral:
- Tablet
- Capsule
- Caplet
- Chewable tablet
- Orally disintegrating tablet (ODT)
- Extended-release (ER, XR, SR)
- Delayed-release (DR)
Liquid oral:
- Solution
- Suspension
- Syrup
- Elixir
- Drops
Parenteral:
- Solution for injection
- Powder for injection (reconstituted)
- Intravenous infusion
- Intramuscular injection
- Subcutaneous injection
Topical:
- Cream
- Ointment
- Gel
- Lotion
- Paste
- Patch (transdermal)
- Foam
- Spray
Other:
- Suppository (rectal, vaginal)
- Inhaler (MDI, DPI)
- Nebulizer solution
- Ophthalmic (drops, ointment)
- Otic (drops)
- Nasal spray
Prescription Writing Elements
Complete prescription includes:
- Patient name and DOB
- Date
- Medication name (generic preferred)
- Strength/concentration
- Dosage form
- Quantity to dispense
- Directions (Sig)
- Number of refills
- Prescriber signature and credentials
- DEA number (for controlled substances)
Sig (Directions for use):
- Clear, specific instructions
- Route of administration
- Frequency
- Duration (if applicable)
- Special instructions
Example:
- "Take one tablet by mouth twice daily with food for 10 days"
- "Apply thin layer to affected area three times daily"
- "Instill 1 drop in each eye every 4 hours while awake"
Anatomical Terminology
Directional Terms
Superior/Inferior:
- Superior: toward the head
- Inferior: toward the feet
- Cranial: toward the head
- Caudal: toward the tail/feet
Anterior/Posterior:
- Anterior: toward the front
- Posterior: toward the back
- Ventral: toward the belly
- Dorsal: toward the back
Medial/Lateral:
- Medial: toward the midline
- Lateral: away from the midline
Proximal/Distal:
- Proximal: closer to the trunk or point of origin
- Distal: farther from the trunk or point of origin
Superficial/Deep:
- Superficial: toward the surface
- Deep: away from the surface
Body Planes
Sagittal plane: Divides body into right and left
- Midsagittal: exactly through midline
- Parasagittal: parallel to midline
Coronal (frontal) plane: Divides body into anterior and posterior
Transverse (axial) plane: Divides body into superior and inferior
Anatomical Position
- Standing upright
- Feet parallel
- Arms at sides
- Palms facing forward
- Head facing forward
Regional Terms
Head and Neck:
- Cephalic: head
- Frontal: forehead
- Orbital: eye
- Nasal: nose
- Oral: mouth
- Cervical: neck
- Occipital: back of head
Trunk:
- Thoracic: chest
- Abdominal: abdomen
- Pelvic: pelvis
- Lumbar: lower back
- Sacral: sacrum
Extremities:
- Brachial: arm
- Antebrachial: forearm
- Carpal: wrist
- Manual: hand
- Digital: fingers/toes
- Femoral: thigh
- Crural: leg
- Tarsal: ankle
- Pedal: foot
Laboratory Units and Conversions
Common Laboratory Units
Hematology:
- RBC: × 10⁶/μL or × 10¹²/L
- WBC: × 10³/μL or × 10⁹/L
- Hemoglobin: g/dL or g/L
- Hematocrit: % or fraction
- Platelets: × 10³/μL or × 10⁹/L
- MCV: fL
- MCHC: g/dL or g/L
Chemistry:
- Glucose: mg/dL or mmol/L
- BUN: mg/dL or mmol/L
- Creatinine: mg/dL or μmol/L
- Sodium, potassium, chloride: mEq/L or mmol/L
- Calcium: mg/dL or mmol/L
- Albumin: g/dL or g/L
- Bilirubin: mg/dL or μmol/L
- Cholesterol: mg/dL or mmol/L
Therapeutic Drug Levels:
- Usually: mcg/mL, ng/mL, or μmol/L
Unit Conversions (Selected)
Glucose:
- mg/dL ÷ 18 = mmol/L
- mmol/L × 18 = mg/dL
Creatinine:
- mg/dL × 88.4 = μmol/L
- μmol/L ÷ 88.4 = mg/dL
Bilirubin:
- mg/dL × 17.1 = μmol/L
- μmol/L ÷ 17.1 = mg/dL
Cholesterol:
- mg/dL × 0.0259 = mmol/L
- mmol/L × 38.67 = mg/dL
Hemoglobin:
- g/dL × 10 = g/L
- g/L ÷ 10 = g/dL
Grading and Staging Systems
Cancer Staging (TNM)
T (Primary Tumor):
- TX: Cannot be assessed
- T0: No evidence of primary tumor
- Tis: Carcinoma in situ
- T1-T4: Size and/or extent of primary tumor
N (Regional Lymph Nodes):
- NX: Cannot be assessed
- N0: No regional lymph node metastasis
- N1-N3: Involvement of regional lymph nodes
M (Distant Metastasis):
- M0: No distant metastasis
- M1: Distant metastasis present
Stage Grouping:
- Stage 0: Tis N0 M0
- Stage I-III: Various T and N combinations, M0
- Stage IV: Any T, any N, M1
NYHA Heart Failure Classification
- Class I: No limitation. Ordinary physical activity does not cause symptoms
- Class II: Slight limitation. Comfortable at rest, ordinary activity causes symptoms
- Class III: Marked limitation. Comfortable at rest, less than ordinary activity causes symptoms
- Class IV: Unable to carry out any physical activity without symptoms. Symptoms at rest
Child-Pugh Score (Liver Disease)
Parameters: Bilirubin, albumin, INR, ascites, encephalopathy
Classes:
- Class A (5-6 points): Well-compensated
- Class B (7-9 points): Significant functional compromise
- Class C (10-15 points): Decompensated
Glasgow Coma Scale
Eye Opening (1-4):
- 4: Spontaneous
- 3: To speech
- 2: To pain
- 1: None
Verbal Response (1-5):
- 5: Oriented
- 4: Confused
- 3: Inappropriate words
- 2: Incomprehensible sounds
- 1: None
Motor Response (1-6):
- 6: Obeys commands
- 5: Localizes pain
- 4: Withdraws from pain
- 3: Abnormal flexion
- 2: Extension
- 1: None
Total Score: 3-15 (3 = worst, 15 = best)
- Severe: ≤8
- Moderate: 9-12
- Mild: 13-15
Medical Prefixes and Suffixes
Common Prefixes
- a-/an-: without, absence (anemia, aphasia)
- brady-: slow (bradycardia)
- dys-: abnormal, difficult (dyspnea, dysuria)
- hyper-: excessive, above (hypertension, hyperglycemia)
- hypo-: below, deficient (hypotension, hypoglycemia)
- poly-: many (polyuria, polydipsia)
- tachy-: fast (tachycardia, tachypnea)
- macro-: large (macrocephaly)
- micro-: small (microcephaly)
- hemi-: half (hemiplegia)
- bi-/di-: two (bilateral, diplopia)
Common Suffixes
- -algia: pain (arthralgia, neuralgia)
- -ectomy: surgical removal (appendectomy, cholecystectomy)
- -emia: blood condition (anemia, leukemia)
- -itis: inflammation (appendicitis, arthritis)
- -oma: tumor (carcinoma, melanoma)
- -osis: abnormal condition (cirrhosis, osteoporosis)
- -pathy: disease (neuropathy, nephropathy)
- -penia: deficiency (thrombocytopenia, neutropenia)
- -plasty: surgical repair (rhinoplasty, angioplasty)
- -scopy: visual examination (colonoscopy, bronchoscopy)
- -stomy: surgical opening (colostomy, tracheostomy)
This reference provides comprehensive medical terminology, coding systems, abbreviations, and nomenclature standards. Use these guidelines to ensure accurate, standardized clinical documentation.
1---2name: 569-medical-terminology-1e74a3c73description: Medical Terminology and Coding Standards4---5# Medical Terminology and Coding Standards67## Standard Nomenclature Systems89### SNOMED CT (Systematized Nomenclature of Medicine - Clinical Terms)1011**Purpose:** Comprehensive clinical terminology for electronic health records1213**Coverage:**14- Clinical findings15- Symptoms16- Diagnoses17- Procedures18- Body structures19- Organisms20- Substances21- Pharmaceutical products22- Specimens2324**Structure:**25- Concepts with unique identifiers26- Descriptions (preferred and synonyms)27- Relationships between concepts28- Hierarchical organization2930**Example:**31- Concept: Myocardial infarction32- SNOMED CT code: 2229800633- Parent: Heart disease34- Children: Acute myocardial infarction, Old myocardial infarction3536**Benefits:**37- Enables semantic interoperability38- Supports clinical decision support39- Facilitates data analytics40- International standard4142### LOINC (Logical Observation Identifiers Names and Codes)4344**Purpose:** Universal code system for laboratory and clinical observations4546**Components of LOINC code:**471. **Component** (analyte or measurement): What is measured482. **Property**: What characteristic (mass, volume, etc.)493. **Timing**: When measured (point in time, 24-hour)504. **System**: Specimen or system (serum, urine, arterial blood)515. **Scale**: Type of result (quantitative, ordinal, nominal)526. **Method**: How measured (when relevant to interpretation)5354**Examples:**55- **Glucose [Mass/volume] in Serum or Plasma**: 2345-756 - Component: Glucose57 - Property: Mass concentration58 - Timing: Point in time59 - System: Serum/Plasma60 - Scale: Quantitative6162- **Hemoglobin A1c/Hemoglobin.total in Blood**: 4548-463 - Component: Hemoglobin A1c/Hemoglobin.total64 - Property: Mass fraction65 - Timing: Point in time66 - System: Blood67 - Scale: Quantitative6869**LOINC Parts:**70- Document types71- Survey instruments72- Clinical attachments73- Radiology codes74- Pathology codes7576### ICD-10-CM (International Classification of Diseases, 10th Revision, Clinical Modification)7778**Purpose:** Diagnosis and procedure coding for billing, epidemiology, and health statistics7980**Structure:**81- Alphanumeric codes (3-7 characters)82- First character: letter (except U)83- Characters 2-3: numbers84- Characters 4-7: alphanumeric (decimal after 3rd character)85- Laterality, severity, encounter type specified8687**Code structure example:**88- **S72.001A**: Fracture of unspecified part of neck of right femur, initial encounter89 - S: Injury category90 - 72: Femur91 - 001: Unspecified part of neck92 - A: Initial encounter for closed fracture93 - Right side indicated by 1 in 5th position9495**Common categories:**96- A00-B99: Infectious diseases97- C00-D49: Neoplasms98- E00-E89: Endocrine, nutritional, metabolic99- F01-F99: Mental and behavioral100- G00-G99: Nervous system101- I00-I99: Circulatory system102- J00-J99: Respiratory system103- K00-K95: Digestive system104- M00-M99: Musculoskeletal105- N00-N99: Genitourinary106- S00-T88: Injury, poisoning107108**Seventh character extensions:**109- A: Initial encounter110- D: Subsequent encounter111- S: Sequela112113**Placeholder X:**114- Used when code requires 7th character but fewer than 6 characters115- Example: T36.0X5A (Adverse effect of penicillins, initial encounter)116117**Combination codes:**118- Single code describing two diagnoses or diagnosis with manifestation119- Example: E11.21 (Type 2 diabetes with diabetic nephropathy)120121### CPT (Current Procedural Terminology)122123**Purpose:** Procedure and service coding for billing124125**Maintained by:** American Medical Association (AMA)126127**Categories:**128- **Category I**: Procedures and services (5-digit numeric codes)129- **Category II**: Performance measurement (4 digits + F)130- **Category III**: Emerging technology (4 digits + T)131132**Category I Sections:**133- 00100-01999: Anesthesia134- 10000-69990: Surgery135- 70000-79999: Radiology136- 80000-89999: Pathology and Laboratory137- 90000-99999: Medicine138- 99000-99607: Evaluation and Management (E/M)139140**E/M Codes (commonly used):**141- **99201-99215**: Office visits (new and established)142- **99221-99239**: Hospital inpatient services143- **99281-99285**: Emergency department visits144- **99291-99292**: Critical care145- **99304-99318**: Nursing facility services146147**Modifiers:**148- Two-digit codes appended to CPT codes149- Indicate service was altered but not changed150- Examples:151 - -25: Significant, separately identifiable E/M service152 - -50: Bilateral procedure153 - -59: Distinct procedural service154 - -76: Repeat procedure by same physician155 - -RT/LT: Right/Left side156157### RxNorm158159**Purpose:** Normalized names for clinical drugs and drug delivery devices160161**Structure:**162- Includes brand and generic names163- Dose forms164- Strengths165- Links to other drug vocabularies (NDC, SNOMED CT)166167**Example:**168- Concept: Amoxicillin 500 MG Oral Capsule169- RxNorm CUI: 308191170- Ingredients: Amoxicillin171- Strength: 500 MG172- Dose Form: Oral Capsule173174## Medical Abbreviations175176### Acceptable Standard Abbreviations177178**Time:**179- q: every (q4h = every 4 hours)180- qd: daily (avoid - use "daily")181- bid: twice daily182- tid: three times daily183- qid: four times daily184- qhs: at bedtime185- prn: as needed186- ac: before meals187- pc: after meals188- hs: at bedtime189190**Routes:**191- PO: by mouth (per os)192- IV: intravenous193- IM: intramuscular194- SC/SQ/subcut: subcutaneous195- SL: sublingual196- PR: per rectum197- NG: nasogastric198- GT: gastrostomy tube199- TD: transdermal200- inh: inhaled201202**Frequency:**203- stat: immediately204- now: immediately205- continuous: without interruption206- PRN: as needed207208**Laboratory:**209- CBC: complete blood count210- BMP: basic metabolic panel211- CMP: comprehensive metabolic panel212- LFTs: liver function tests213- PT/INR: prothrombin time/international normalized ratio214- PTT/aPTT: partial thromboplastin time/activated PTT215- ESR: erythrocyte sedimentation rate216- CRP: C-reactive protein217- ABG: arterial blood gas218- UA: urinalysis219- HbA1c: hemoglobin A1c220221**Diagnoses:**222- HTN: hypertension223- DM: diabetes mellitus224- CHF: congestive heart failure225- CAD: coronary artery disease226- COPD: chronic obstructive pulmonary disease227- CVA: cerebrovascular accident228- MI: myocardial infarction229- PE: pulmonary embolism230- DVT: deep vein thrombosis231- UTI: urinary tract infection232- CKD: chronic kidney disease233- ESRD: end-stage renal disease234235**Physical Examination:**236- HEENT: head, eyes, ears, nose, throat237- PERRLA: pupils equal, round, reactive to light and accommodation238- EOMI: extraocular movements intact239- JVP: jugular venous pressure240- RRR: regular rate and rhythm241- CTAB: clear to auscultation bilaterally242- BS: bowel sounds or breath sounds (context dependent)243- NT/ND: non-tender, non-distended244- FROM: full range of motion245246**Vital Signs:**247- BP: blood pressure248- HR: heart rate249- RR: respiratory rate250- T or Temp: temperature251- SpO2: oxygen saturation252- Wt: weight253- Ht: height254- BMI: body mass index255256### Do Not Use Abbreviations (Joint Commission)257258**Prohibited abbreviations:**259260| Abbreviation | Intended Meaning | Problem | Use Instead |261|--------------|------------------|---------|-------------|262| U | Unit | Mistaken for 0, 4, or cc | Write "unit" |263| IU | International Unit | Mistaken for IV or 10 | Write "international unit" |264| Q.D., QD, q.d., qd | Daily | Mistaken for each other | Write "daily" |265| Q.O.D., QOD, q.o.d., qod | Every other day | Mistaken for QD or QID | Write "every other day" |266| Trailing zero (X.0 mg) | X mg | Decimal point missed | Never write zero after decimal (write X mg) |267| Lack of leading zero (.X mg) | 0.X mg | Decimal point missed | Always write zero before decimal (write 0.X mg) |268| MS, MSO4, MgSO4 | Morphine sulfate or magnesium sulfate | Confused for each other | Write "morphine sulfate" or "magnesium sulfate" |269270**Additional problematic abbreviations:**271- µg: micrograms (mistaken for mg) → write "mcg"272- cc: cubic centimeters → write "mL"273- hs: half-strength or hour of sleep → write "half-strength" or "bedtime"274- TIW: three times a week → write "three times weekly"275- SC, SQ: subcutaneous → write "subcut" or "subcutaneous"276- D/C: discharge or discontinue → write full word277- AS, AD, AU: left ear, right ear, both ears → write "left ear," "right ear," "both ears"278- OS, OD, OU: left eye, right eye, both eyes → write "left eye," "right eye," "both eyes"279280## Medication Nomenclature281282### Generic vs. Brand Names283284**Best practice:** Use generic names in medical documentation285286**Examples:**287- Acetaminophen (generic) vs. Tylenol (brand)288- Ibuprofen (generic) vs. Advil, Motrin (brand)289- Atorvastatin (generic) vs. Lipitor (brand)290- Metformin (generic) vs. Glucophage (brand)291- Lisinopril (generic) vs. Zestril, Prinivil (brand)292293**When to include brand:**294- Patient education (recognition)295- Novel drugs without generic296- Narrow therapeutic index drugs with bioequivalence issues297- Biologic products298299### Dosage Forms300301**Solid oral:**302- Tablet303- Capsule304- Caplet305- Chewable tablet306- Orally disintegrating tablet (ODT)307- Extended-release (ER, XR, SR)308- Delayed-release (DR)309310**Liquid oral:**311- Solution312- Suspension313- Syrup314- Elixir315- Drops316317**Parenteral:**318- Solution for injection319- Powder for injection (reconstituted)320- Intravenous infusion321- Intramuscular injection322- Subcutaneous injection323324**Topical:**325- Cream326- Ointment327- Gel328- Lotion329- Paste330- Patch (transdermal)331- Foam332- Spray333334**Other:**335- Suppository (rectal, vaginal)336- Inhaler (MDI, DPI)337- Nebulizer solution338- Ophthalmic (drops, ointment)339- Otic (drops)340- Nasal spray341342### Prescription Writing Elements343344**Complete prescription includes:**3451. Patient name and DOB3462. Date3473. Medication name (generic preferred)3484. Strength/concentration3495. Dosage form3506. Quantity to dispense3517. Directions (Sig)3528. Number of refills3539. Prescriber signature and credentials35410. DEA number (for controlled substances)355356**Sig (Directions for use):**357- Clear, specific instructions358- Route of administration359- Frequency360- Duration (if applicable)361- Special instructions362363**Example:**364- "Take one tablet by mouth twice daily with food for 10 days"365- "Apply thin layer to affected area three times daily"366- "Instill 1 drop in each eye every 4 hours while awake"367368## Anatomical Terminology369370### Directional Terms371372**Superior/Inferior:**373- Superior: toward the head374- Inferior: toward the feet375- Cranial: toward the head376- Caudal: toward the tail/feet377378**Anterior/Posterior:**379- Anterior: toward the front380- Posterior: toward the back381- Ventral: toward the belly382- Dorsal: toward the back383384**Medial/Lateral:**385- Medial: toward the midline386- Lateral: away from the midline387388**Proximal/Distal:**389- Proximal: closer to the trunk or point of origin390- Distal: farther from the trunk or point of origin391392**Superficial/Deep:**393- Superficial: toward the surface394- Deep: away from the surface395396### Body Planes397398**Sagittal plane:** Divides body into right and left399- Midsagittal: exactly through midline400- Parasagittal: parallel to midline401402**Coronal (frontal) plane:** Divides body into anterior and posterior403404**Transverse (axial) plane:** Divides body into superior and inferior405406### Anatomical Position407408- Standing upright409- Feet parallel410- Arms at sides411- Palms facing forward412- Head facing forward413414### Regional Terms415416**Head and Neck:**417- Cephalic: head418- Frontal: forehead419- Orbital: eye420- Nasal: nose421- Oral: mouth422- Cervical: neck423- Occipital: back of head424425**Trunk:**426- Thoracic: chest427- Abdominal: abdomen428- Pelvic: pelvis429- Lumbar: lower back430- Sacral: sacrum431432**Extremities:**433- Brachial: arm434- Antebrachial: forearm435- Carpal: wrist436- Manual: hand437- Digital: fingers/toes438- Femoral: thigh439- Crural: leg440- Tarsal: ankle441- Pedal: foot442443## Laboratory Units and Conversions444445### Common Laboratory Units446447**Hematology:**448- RBC: × 10⁶/μL or × 10¹²/L449- WBC: × 10³/μL or × 10⁹/L450- Hemoglobin: g/dL or g/L451- Hematocrit: % or fraction452- Platelets: × 10³/μL or × 10⁹/L453- MCV: fL454- MCHC: g/dL or g/L455456**Chemistry:**457- Glucose: mg/dL or mmol/L458- BUN: mg/dL or mmol/L459- Creatinine: mg/dL or μmol/L460- Sodium, potassium, chloride: mEq/L or mmol/L461- Calcium: mg/dL or mmol/L462- Albumin: g/dL or g/L463- Bilirubin: mg/dL or μmol/L464- Cholesterol: mg/dL or mmol/L465466**Therapeutic Drug Levels:**467- Usually: mcg/mL, ng/mL, or μmol/L468469### Unit Conversions (Selected)470471**Glucose:**472- mg/dL ÷ 18 = mmol/L473- mmol/L × 18 = mg/dL474475**Creatinine:**476- mg/dL × 88.4 = μmol/L477- μmol/L ÷ 88.4 = mg/dL478479**Bilirubin:**480- mg/dL × 17.1 = μmol/L481- μmol/L ÷ 17.1 = mg/dL482483**Cholesterol:**484- mg/dL × 0.0259 = mmol/L485- mmol/L × 38.67 = mg/dL486487**Hemoglobin:**488- g/dL × 10 = g/L489- g/L ÷ 10 = g/dL490491## Grading and Staging Systems492493### Cancer Staging (TNM)494495**T (Primary Tumor):**496- TX: Cannot be assessed497- T0: No evidence of primary tumor498- Tis: Carcinoma in situ499- T1-T4: Size and/or extent of primary tumor500501**N (Regional Lymph Nodes):**502- NX: Cannot be assessed503- N0: No regional lymph node metastasis504- N1-N3: Involvement of regional lymph nodes505506**M (Distant Metastasis):**507- M0: No distant metastasis508- M1: Distant metastasis present509510**Stage Grouping:**511- Stage 0: Tis N0 M0512- Stage I-III: Various T and N combinations, M0513- Stage IV: Any T, any N, M1514515### NYHA Heart Failure Classification516517- **Class I**: No limitation. Ordinary physical activity does not cause symptoms518- **Class II**: Slight limitation. Comfortable at rest, ordinary activity causes symptoms519- **Class III**: Marked limitation. Comfortable at rest, less than ordinary activity causes symptoms520- **Class IV**: Unable to carry out any physical activity without symptoms. Symptoms at rest521522### Child-Pugh Score (Liver Disease)523524**Parameters:** Bilirubin, albumin, INR, ascites, encephalopathy525526**Classes:**527- **Class A (5-6 points)**: Well-compensated528- **Class B (7-9 points)**: Significant functional compromise529- **Class C (10-15 points)**: Decompensated530531### Glasgow Coma Scale532533**Eye Opening (1-4):**534- 4: Spontaneous535- 3: To speech536- 2: To pain537- 1: None538539**Verbal Response (1-5):**540- 5: Oriented541- 4: Confused542- 3: Inappropriate words543- 2: Incomprehensible sounds544- 1: None545546**Motor Response (1-6):**547- 6: Obeys commands548- 5: Localizes pain549- 4: Withdraws from pain550- 3: Abnormal flexion551- 2: Extension552- 1: None553554**Total Score:** 3-15 (3 = worst, 15 = best)555- Severe: ≤8556- Moderate: 9-12557- Mild: 13-15558559## Medical Prefixes and Suffixes560561### Common Prefixes562563- **a-/an-**: without, absence (anemia, aphasia)564- **brady-**: slow (bradycardia)565- **dys-**: abnormal, difficult (dyspnea, dysuria)566- **hyper-**: excessive, above (hypertension, hyperglycemia)567- **hypo-**: below, deficient (hypotension, hypoglycemia)568- **poly-**: many (polyuria, polydipsia)569- **tachy-**: fast (tachycardia, tachypnea)570- **macro-**: large (macrocephaly)571- **micro-**: small (microcephaly)572- **hemi-**: half (hemiplegia)573- **bi-/di-**: two (bilateral, diplopia)574575### Common Suffixes576577- **-algia**: pain (arthralgia, neuralgia)578- **-ectomy**: surgical removal (appendectomy, cholecystectomy)579- **-emia**: blood condition (anemia, leukemia)580- **-itis**: inflammation (appendicitis, arthritis)581- **-oma**: tumor (carcinoma, melanoma)582- **-osis**: abnormal condition (cirrhosis, osteoporosis)583- **-pathy**: disease (neuropathy, nephropathy)584- **-penia**: deficiency (thrombocytopenia, neutropenia)585- **-plasty**: surgical repair (rhinoplasty, angioplasty)586- **-scopy**: visual examination (colonoscopy, bronchoscopy)587- **-stomy**: surgical opening (colostomy, tracheostomy)588589---590591This reference provides comprehensive medical terminology, coding systems, abbreviations, and nomenclature standards. Use these guidelines to ensure accurate, standardized clinical documentation.592