Bursitis is the acute or chronic inflammation of a bursa, a small synovial-membrane-lined, fluid-filled sac strategically located between bones, tendons, muscles, and skin at high-friction sites throughout the body, most commonly at the shoulder, hip, elbow, and knee. It is distinguished from arthritis, which involves inflammation within the joint space itself; bursitis is periarticular — meaning it occurs adjacent to, not inside, the joint — although the two conditions frequently coexist and can be clinically difficult to differentiate without imaging. The underlying mechanism involves irritation, trauma, infection, crystal deposition (as in gout or pseudogout), or autoimmune processes that trigger synovial lining inflammation, leading to excess bursal fluid accumulation, distension, and pain with movement or palpation. Bursitis can be physiological in a minor sense — temporary bursal irritation from repetitive motion is common and often self-limiting — but pathological bursitis is the clinically coded entity, defined by persistent inflammation requiring medical intervention. The most clinically relevant coding subtypes are organized by anatomic site (M70.-M71. ranges) with specific codes for shoulder (subacromial/subdeltoid), hip (trochanteric), elbow (olecranon), and knee (prepatellar/infrapatellar) involvement. Bursitis is commonly confused with tendinitis, which involves tendoninflammation rather than bursal inflammation, though the two often coexist — particularly at the shoulder, where subacromial bursitis and rotator cuff tendinitis are nearly inseparable clinically.
Greek -ῖτις (-itis), from nosos (disease) + feminine suffix
Noun-forming suffix — “inflammation of” — standard medical suffix denoting inflammatory disease of the named structure
The word entered English in the 1840s as bursitis (noun), constructed from Medieval Latin bursa (“pouch, purse”), from Greek βύρσα (búrsa, “hide, wineskin, pouch”), combined with the Greek inflammatory suffix -itis — literally “inflammation of the pouch.” The anatomical term bursa was applied by early anatomists as a structural metaphor for these small, purse-like sacs cushioning joint structures; the term bursa mucosa appeared in anatomical Latin by the 17th century. The root burs- (“pouch”) connects bursitis to related anatomical terms: bursa (burs- → pouch), bursal (pouch-related), and bursectomy (burs- + -ectomy → surgical removal of the bursa). The suffix -itis is among the most productive in all of medical terminology, appearing in arthritis, tendinitis, synovitis, fasciitis, and cellulitis.
🔀 ALIASES / ALTERNATE TERMS
Bursal(adjective form — common clinical collocations include “bursal inflammation,” “bursal effusion,” “bursal thickening” on imaging reports and operative notes)
Periarthritis(clinical synonym used when bursitis is accompanied by surrounding soft tissue inflammation; common in shoulder periarthritis — coded under M75.0-M75.5)
Subacromial bursitis(most common form of shoulder bursitis; located beneath the acromion and above the rotator cuff; frequently coexists with rotator cuff pathology; M75.5)
Subdeltoid bursitis(anatomic variant of subacromial bursitis; the subacromial and subdeltoid bursae communicate in most patients and are often coded together; M75.5)
Trochanteric bursitis(hip bursitis at the greater trochanter; one of the most common lower extremity bursal conditions; M70.60-M70.62; now reclassified under greater trochanteric pain syndrome in current literature)
Olecranon bursitis(elbow bursitis over the olecranon process; can be septic or aseptic; M70.20-M70.22; also called “student’s elbow” or “miner’s elbow”)
Prepatellar bursitis(knee bursitis anterior to the patella; M70.40-M70.42; also called “housemaid’s knee” — occupational/positional etiology)
Infrapatellar bursitis(bursitis below the patella at the patellar tendon insertion; M70.50-M70.52; also called “clergyman’s knee”)
Septic bursitis(infectious form caused most commonly by Staphylococcus aureus; coded with M71.0x- for primary site plus B95-B97 organism code; requires aspiration and antibiotic therapy)
Calcific bursitis(calcium pyrophosphate or hydroxyapatite crystal deposition in the bursa; often associated with chronic shoulder bursitis; M71.40-M71.42)
Adventitious bursitis(newly formed bursa developing over a bony prominence due to chronic pressure/friction — e.g., over a bunion or at a bony spur; M71.30-M71.38)
🔗 RELATED TERMS
Arthritis — inflammation within the joint space itself, as opposed to the periarticular location of bursitis; distinguished by intra-articular effusion, synovitis, and cartilage involvement on imaging; frequently coexists with bursitis, particularly in rheumatoid and crystal arthropathies
tendinitis — inflammation of a tendon rather than a bursa; shares clinical presentation of focal pain and swelling near joints; often coexists with bursitis (e.g., subacromial bursitis + rotator cuff tendinitis at M75.1-M75.5); coded separately when both documented
Synovitis — inflammation of the synovial lining, which also lines bursal sacs; synovitis (M65.-) refers primarily to joint-space synovial inflammation but the pathophysiology overlaps with bursal inflammation
Bursa — the anatomical structure that becomes inflamed in bursitis; a closed, fluid-filled synovial sac reducing friction between moving structures
Bursectomy — surgical excision of a chronically inflamed or calcified bursa; CPT 27062 (trochanteric), 23030-23031 (shoulder drainage); coded when conservative treatment fails
Gout — crystal arthropathy caused by urate crystal deposition; can cause secondary bursitis, most classically at the olecranon bursa; coded with M10.- plus the bursal site when both documented
Pseudogout — calcium pyrophosphate crystal deposition disease; can deposit in bursae and cause calcific bursitis; M11.-
Rheumatoid arthritis — systemic autoimmune inflammatory arthropathy (M05.-, M06.-) that commonly causes bursitis as a periarticular manifestation; bursitis in RA patients is coded additionally when separately documented
Septic arthritis — infectious joint inflammation; distinguished from septic bursitis by its intra-articular location; both require organism coding (B95-B97) and may require surgical drainage
Rotator cuff syndrome — umbrella term for subacromial impingement, subacromial bursitis, and rotator cuff tendinopathy; M75.1; bursitis is often the dominant pain generator within this syndrome
MRI — primary diagnostic imaging modality for confirming bursal effusion, thickening, and associated structural pathology; distinguishes bursitis from tendon tears, joint effusion, and soft tissue masses
Ultrasonic guidance for needle placement (e.g., biopsy, aspiration, injection, localization device), imaging supervision and interpretation (companion code — used with aspiration/injection CPTs when ultrasound guidance is separately documented)
Therapeutic procedure, 1 or more areas, each 15 minutes; therapeutic exercises to develop strength and endurance, range of motion and flexibility (rehabilitation phase)
Therapeutic activities, direct (one-on-one) patient contact by the provider; each 15 minutes (functional activity retraining for bursitis-related ADL limitations)
⚠️ Coding Note:Bursitis codes in the M70.- and M71.- ranges require laterality at the highest level of specificity available — always assign right, left, or bilateral rather than defaulting to “unspecified” when the documentation supports site identification. On inpatient profee claims, bursitis is rarely the principal diagnosis but frequently appears as a secondary diagnosis driving orthopedic consults, PT/OT orders, or injection procedures; sequence the underlying or admitting condition first unless bursitis is the direct reason for the encounter. A critical undercoding alert: septic bursitis (M71.0x-) requires an additional code for the causative organism (B95.- for streptococcus/staph, B96.- for other bacteria) — the documentation trigger phrase “infected bursa,” “bursal abscess,” or “purulent aspirate from bursa” should prompt a query for the specific organism if not documented. When ultrasound guidance is used for bursal aspiration or injection, 20611 or 20606 replaces — not appends to — the non-guided code (20610/20605); both cannot be billed together for the same encounter and site. For calcific bursitis at the shoulder, consider whether M75.3 (calcific tendinitis of shoulder) is a more appropriate code when the calcification is primarily tendinous rather than bursal, as the distinction matters for accurate MS-DRG grouping.
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