-clud-

DEFINITION of -clud-

The combining form -clud- (also appearing as -clus- in its past-participial form and -clude as a suffix) comes from the Latin verb claudere — meaning to close, shut, or block. In medical terminology, it appears most prominently in occlusion and its derivatives, where it describes the complete or partial blocking of a vessel, passage, or anatomical structure. The root surfaces across multiple specialties: in cardiology as coronary artery occlusion; in dentistry as malocclusion (abnormal tooth contact when jaws close); in ophthalmology as retinal artery occlusion; and in vascular surgery as arterial occlusion and venous occlusion. For AAPC-certified inpatient profee coders, -clud- terms are high-stakes — occlusion codes carry CC and MCC status in many DRGs, and specificity of vessel, laterality, acuity (acute vs. chronic), and type (thrombotic vs. embolic vs. atherosclerotic) all directly affect DRG assignment, query generation, and risk-adjusted reimbursement. Missing or undercoding an occlusion diagnosis is one of the most impactful clinical documentation improvement (CDI) gaps in inpatient profee coding.

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ETYMOLOGY of -clud-

latin

• Origin: Latin verb claudere — “to shut, close, or make fast”
• Past participle stem: clausus / clusus → gives the variant -clus- (as in occlusion, exclusion, inclusion, conclusion)
• Proto-Indo-European root: *klāu- — “hook, peg, nail” — the physical object used to fasten or shut a door
• Grammatical function in Latin: Verb root combined with directional prefixes to create new verbs expressing how something is shut
• Meaning evolution:
  • Classical Latin: claudere = to close a door, gate, or passage; occludere = to shut against/block; includere = to shut in; excludere = to shut out
  • Medical Latin (17th-19th c.): Extended to describe vascular, dental, and anatomical blockages and closures
  • Modern medical usage: Standardized across cardiology, dentistry, ophthalmology, and vascular medicine
• Entry into English: Via Old French -clure / -clusion and directly from Latin past participle stems
• Key prefix combinations with -clud-:
  • ob- + claudere → occludere → occlude (to block against)
  • in- + claudere → includere → include (to shut in)
  • ex- + claudere → excludere → exclude (to shut out)
  • con- + claudere → concludere → conclude (to shut together/end)
  • pre- + claudere → praecludere → preclude (to shut before/prevent)
• Related root: cleis- / cleist- (Greek equivalent — “to close”) as in anaclisis; distinct from -cid- (to cut/kill)

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RELATED TERMS to -clud- / -clus-

-clud- / -clus- Term	Prefix + Root	Literal Meaning	Medical Meaning
occlusion	ob- + claudere	”shut against”	Blockage of a vessel or tooth contact
malocclusion	mal- + occlusio	”bad closing”	Abnormal dental bite alignment
inclusion	in- + claudere	”shut in”	Enclosure; inclusion body (pathology)
exclusion	ex- + claudere	”shut out”	Surgical bypass or isolation of structure
occlusive	occlusus + -ivus	”pertaining to shutting”	Describing a blocking agent or dressing
reclusion	re- + claudere	”shut back/again”	Confinement; used in psych contexts
preclude	prae- + claudere	”shut before”	Prevent; contraindicate

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CLINICAL & CODING USES (-clud- terms & coding applications)

Cardiology / Vascular (Highest-volume -clud- coding area):

• Coronary artery occlusion: Acute → likely AMI; chronic → atherosclerotic disease — specificity of vessel (LAD, RCA, LCX) and acuity is mandatory for ICD-10-CM
• Arterial occlusion: Peripheral arteries — code by vessel + laterality + acute vs. chronic; affects DRG 299/300 assignment
• Venous occlusion: DVT vs. venous thrombosis vs. occlusion without thrombosis — distinct codes, do not default to unspecified
• Retinal artery occlusion / Retinal vein occlusion: Ophthalmology — laterality (right/left/bilateral) required; central vs. branch vessel further specifies

Dentistry / Oral Surgery:

• Malocclusion: Coded by Angle’s classification (Class I, II, III) — requires provider documentation of class; unspecified is available but query-worthy
• Occlusal trauma: Documented in dental/oral surgery notes; may support periodontitis or TMJ codes
• Dental occlusion: Functional vs. dysfunctional; drives M26 code family

Pulmonology / Airway:

• Airway occlusion: Foreign body vs. mucus plug vs. tumor — mechanism drives code selection; affects MCC capture
• Occlusive dressing: Documented in wound care; relevant for CPT billing of wound management services

Profee Coding Tips:

• Always query: acute vs. chronic, vessel specificity, laterality, thrombotic vs. embolic vs. atherosclerotic — all change the code and DRG weight
• Occlusion as CC/MCC: Many vascular occlusion codes serve as CCs or MCCs — missing them = lost DRG weight; flag for CDI
• NCCI edits: Watch for bundling when vascular occlusion treatment (e.g., thrombectomy) is coded alongside diagnostic angiography — use modifier -59 only when truly distinct
• Modifier -LT / -RT: Required for lateralized occlusion procedures (retinal, peripheral arterial)
• Modifier -50: Bilateral retinal or peripheral vascular occlusion procedures when both sides addressed

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ICD-10 & CPT Quick Reference

✅ Valid & Billable ICD-10-CM Diagnosis Codes:

Code	Description
I21.09	ST elevation MI involving other coronary artery of anterior wall (acute coronary occlusion)
I25.10	Atherosclerotic heart disease of native coronary artery without angina pectoris (chronic occlusion)
I74.01	Saddle embolus of abdominal aorta (aortic occlusion)
I74.3	Embolism and thrombosis of arteries of the lower extremities
I74.4	Embolism and thrombosis of arteries of the lower extremities, unspecified
I70.211	Atherosclerosis of native arteries of extremities with intermittent claudication, right leg
I70.212	Atherosclerosis of native arteries of extremities with intermittent claudication, left leg
H34.11	Central retinal artery occlusion, right eye
H34.12	Central retinal artery occlusion, left eye
H34.231	Retinal artery branch occlusion, right eye
H34.232	Retinal artery branch occlusion, left eye
H34.811	Central retinal vein occlusion, right eye
H34.812	Central retinal vein occlusion, left eye
M26.211	Malocclusion, Angle’s class I
M26.212	Malocclusion, Angle’s class II
M26.213	Malocclusion, Angle’s class III
M26.219	Malocclusion, unspecified Angle’s class
M26.57	Lack of posterior occlusal support

✅ Valid & Billable CPT Codes:

Code	Description
92920	Percutaneous transluminal coronary angioplasty; single major coronary artery or branch (occlusion treatment)
92928	Percutaneous transcatheter placement of intracoronary stent(s) with coronary angioplasty; single major coronary artery or branch
34051	Embolectomy/thrombectomy, aortic, abdominal (occlusion removal)
34201	Embolectomy/thrombectomy, femoropopliteal, popliteal, tibio-peroneal artery, by leg
67228	Laser photocoagulation of retinal lesion; extensive, one or more sessions (retinal vein occlusion)
67210	Destruction of localized lesion of retina; one session — retinal occlusion laser
21085	Oral surgical splint (occlusal device — dental/oral surgery)
70336	MRI temporomandibular joint(s) — evaluates occlusal/TMJ dysfunction

✅ Valid Modifiers:

Modifier	Use
-59	Distinct procedural service — e.g., diagnostic angiography distinct from occlusion intervention
-LT	Left side — retinal, peripheral arterial, or venous occlusion procedures
-RT	Right side — same
-50	Bilateral — bilateral retinal vein/artery occlusion treatment
-80	Assistant surgeon — complex vascular occlusion open surgical cases
-26	Professional component — when reading diagnostic imaging for occlusion evaluation

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DERIVATIONS of -clud-

TABLE definition AS Definition
WHERE length(filter(roots, (word) => econtains(this.roots, word))) > 0 AND file.name != this.file.name
SORT file.name ASC

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Query functionality

TABLE definition AS Definition
FROM #medroot
WHERE length(filter(definition, (word) => econtains(this.definition, word))) > 0 AND file.name != this.file.name

Med roots dictionary Appendix A Prefixes Appendix B Combining Forms Appendix C Suffixes Appendix D Suffix forms