Anatomy & Physiology for Medical Coders — Quick Reference
Directional terms
|---|---|
| Anterior / Posterior | Front / back |
|---|
| Superior / Inferior | Above / below |
| Medial / Lateral | Toward / away from the body's midline |
| Proximal / Distal | Closer to / farther from the point of attachment |
Body systems — coding relevance at a glance
| System | Key coding consideration |
|---|
|---|---|
| Skeletal | Bone + site + laterality + encounter type required for fractures |
|---|
| Muscular | Injury/strain codes reference specific muscle groups |
| Cardiovascular | High-volume, dense area — chamber/valve/vessel specificity |
| Respiratory | Upper (nose–trachea) vs. lower (bronchi–lungs) — different chapters |
| Digestive | Organ specificity required (esophagus, stomach, intestines, liver, pancreas) |
| Nervous | Stroke/neuropathy coding depends on precise location |
| Genitourinary | CKD staged 1-5 by GFR — stage drives code selection |
| Integumentary | Burns: site + depth/degree + TBSA (Rule of Nines) |
| Endocrine | Diabetes coded WITH documented complications as combination codes |
CKD staging by GFR
|---|---|
| 1 | ≥ 90 |
|---|
| 2 | 60–89 |
| 3a / 3b | 45–59 / 30–44 |
| 4 | 15–29 |
| 5 | < 15 (often dialysis) |
7th character extensions (injury coding)
A — Initial encounter (active treatment)
D — Subsequent encounter (routine healing)
S — Sequela (a residual/late effect after the acute event resolved)
Diabetes complication pathway
Chronic hyperglycemia damages:
→ Retina (small vessels) → diabetic retinopathy
→ Nephrons → diabetic nephropathy → CKD
→ Peripheral nerves → diabetic neuropathy
→ Vasculature (macrovascular) → cardiovascular risk
Coded as a COMBINATION code (diabetes + complication together),
not as separate independent diagnoses.
Acute vs. chronic — quick distinction
Acute — sudden onset, typically reversible/resolving
Chronic — long-standing, typically progressive
Acute-on-chronic — both can coexist; documentation must specify which
Red flags requiring a physician query, not coder inference
[ ] "Possible" / "rule out" diagnosis language — not yet confirmed
[ ] GFR value present but no documented CKD stage
[ ] Ambiguous laterality on a fracture/injury
[ ] Unclear whether a secondary condition is causally related to
the primary diagnosis (CC/MCC determination)
