-asis

DEFINITION of -asis

The suffix -asis (also appearing as -iasis) means a condition, formation, or pathological presence of something — indicating a state of disease, an abnormal process, or the existence of a substance within the body. It functions as a noun-forming suffix that turns a root word into the name of a chronic or ongoing condition, often implying infestation, accumulation, or a pathological state rather than acute inflammation (compare -itis). The variant -iasis is the more commonly seen form in clinical terminology and is used specifically for conditions caused by parasites, fungi, or abnormal deposits (e.g., cholelithiasis = presence of gallstones; candidiasis = condition caused by Candida fungus; filariasis = infestation by filarial worms). Unlike -osis (which also denotes a condition but leans toward degenerative or proliferative processes), -asis and -iasis tend to describe conditions defined by the presence or infestation of a specific agent or substance. For AAPC-certified inpatient profee coders, recognizing -asis/-iasis is critical because these conditions often drive principal diagnosis selection, CC/MCC capture, and MS-DRG assignment, particularly in infectious disease, urology, and GI coding.

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ETYMOLOGY of -asis

greek #latin

• Origin: Latin -iasis, denoting a pathological condition or process; derived from Ancient Greek íasis (ἴασις) — originally meaning “cure, repair, or mending”
• Semantic irony: The Greek root íasis meant healing, but the suffix evolved in medical Latin to denote the condition requiring healing — i.e., the disease state itself
• Root verb: Greek iáomai (ἰάομαι) — “to heal, to cure”
• Meaning evolution:
  • Classical Greek: íasis = the act of healing or a cure
  • Hellenistic/medical Greek: Shifted to describe the pathological state or process (what is being healed)
  • Latin medical adoption: Formalized as -iasis in New Latin for naming chronic conditions and infestations
  • Modern English: Standardized in clinical terminology for parasitic, fungal, lithiasis (stone-forming), and other chronic conditions
• Entry into English: Via New Latin medical vocabulary, widely adopted in the 18th-19th centuries as taxonomy of infectious and parasitic diseases expanded
• Variant form: -asis appears in older or simplified compound forms (e.g., psoriasis, mydriasis); -iasis is the productive modern form (e.g., cholelithiasis, ureterolithiasis)
• Related suffixes: -osis (condition/process, often degenerative), -ia (disease/abnormal state), -ism (condition/state)

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RELATED TERMS to -asis / -iasis

-asis / -iasis Term	Combining Root	Meaning
psoriasis	Greek psōra- (itch)	Chronic skin condition with scaly plaques
mydriasis	Greek mydriān (dilate)	Pathological dilation of the pupil
cholelithiasis	e- + o- (bile + stone)	Presence of gallstones
nephrolithiasis	o- + o- (kidney + stone)	Presence of kidney stones
ureterolithiasis	o- + o-	Stones in the ureter
urolithiasis	o- + o-	Stones anywhere in urinary tract
candidiasis	Candida (genus name)	Fungal infection by Candida species
filariasis	Latin filum (thread)	Parasitic worm infestation
leishmaniasis	Leishmania (genus)	Parasitic protozoan infection
choledocholithiasis	o- + o-	Stones in the common bile duct

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CLINICAL USES (-asis/-iasis conditions & coding applications)

Urology (High-frequency -iasis coding territory for profee):

• Nephrolithiasis: Kidney stones — query stone location, laterality, and any obstruction for full ICD-10 specificity
• Ureterolithiasis: Ureteral calculi — laterality required; drives codes like N20.1
• Urolithiasis: Unspecified urinary tract stones — use only when site cannot be determined
• Cholelithiasis / Choledocholithiasis: Gallstones / CBD stones — query for obstruction, acute cholecystitis, and whether cholecystectomy is performed

Dermatology:

• Psoriasis: Chronic autoimmune skin disease — query type (plaque, guttate, pustular, erythrodermic) and whether psoriatic arthritis is present; type drives both ICD-10 and potential biologics (HCPCS)
• Pityriasis: Scaly skin condition — verify type (rosea, rubra pilaris, versicolor) for specificity

Ophthalmology:

• Mydriasis: Pathological pupil dilation — distinguish from pharmacologically induced (procedure-related) dilation for accurate coding

Infectious Disease / Parasitology:

• Candidiasis: Query site (oral, esophageal, vaginal, systemic) — each maps to a different ICD-10 code family
• Leishmaniasis / Filariasis: Tropical parasitic conditions — important for inpatient admissions in travel medicine

Profee Coding Tips:

• -iasis conditions are frequently CC/MCCs — always check if they elevate MS-DRG (e.g., choledocholithiasis with obstruction vs. without)
• Laterality matters: Kidney/ureteral stone codes require left, right, or bilateral — query radiology reports
• Obstruction is a separate axis: Stones with obstruction = significantly different codes and DRG weight — never assume; always query
• Modifier -59: Use when -iasis diagnosis drives a separately identifiable procedure at same encounter
• Modifier -25: Significant, separately identifiable E/M on same day as procedure (e.g., office visit + cystoscopy for urolithiasis)

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ICD-10 & CPT Quick Reference

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

Code	Description
N20.0	Calculus of kidney (nephrolithiasis)
N20.1	Calculus of ureter (ureterolithiasis)
N20.2	Calculus of kidney with calculus of ureter
N20.9	Urinary calculus, unspecified (urolithiasis)
K80.20	Calculus of gallbladder without cholecystitis, without obstruction (cholelithiasis)
K80.21	Calculus of gallbladder without cholecystitis, with obstruction
K80.50	Calculus of bile duct without cholangitis/cholecystitis, without obstruction (choledocholithiasis)
K80.51	Calculus of bile duct without cholangitis/cholecystitis, with obstruction
B37.0	Candidal stomatitis (oral candidiasis)
B37.1	Pulmonary candidiasis
B37.3	Candidiasis of vulva and vagina
B37.81	Candidal esophagitis
B37.89	Other sites of candidiasis
L40.0	Plaque psoriasis
L40.1	Generalized pustular psoriasis
L40.4	Guttate psoriasis
L40.50	Arthropathic psoriasis, unspecified
H57.04	Mydriasis

✅ Valid & Billable CPT Codes (conditions driven by -iasis):

Code	Description
50590	Lithotripsy, extracorporeal shock wave (ESWL) — nephrolithiasis / ureterolithiasis
52352	Cystourethroscopy with ureteroscopy; with removal or manipulation of ureteral calculus
52353	Cystourethroscopy with ureteroscopy; with lithotripsy (ureteral stone)
47562	Laparoscopic cholecystectomy — cholelithiasis without common duct exploration
47563	Laparoscopic cholecystectomy with cholangiography
43239	EGD with injection — may be used in esophageal candidiasis workup
96372	Therapeutic injection (IM/SQ) — antifungal administration for candidiasis

✅ Valid Modifiers:

Modifier	Use
-59	Distinct procedural service — separate -iasis-driven procedure at same encounter
-25	Significant, separately identifiable E/M same day as minor procedure
-50	Bilateral procedure — relevant for bilateral kidney/ureteral stones
-LT / -RT	Left side / Right side — required for lateralized stone procedures

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DERIVATIONS of -asis

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