What does complication mean?
A complication is an additional difficulty or adverse circumstance that makes an already existing situation more difficult to deal with. The word is most commonly used when plans, negotiations, or processes encounter unforeseen problems — a legal dispute might face complications from missing documents, for instance. It also has a well-established and precise medical meaning: a complication is a secondary problem that develops during or as a result of an illness, operation, or course of treatment, such as an infection following surgery. Derived from the Latin verb 'complicare', meaning 'to fold together', the word carries an inherently negative connotation — nobody welcomes a complication, since by definition it obstructs progress rather than aiding it. Its usefulness lies in its flexibility: it can describe anything from a minor logistical snag to a serious clinical setback, making it a versatile word in both everyday conversation and formal, technical writing.
A thing, circumstance, or event that adds difficulty or complexity to a situation.
"Bad weather proved an unexpected complication during the rescue mission."
Often used with verbs such as 'add', 'cause', or 'create', e.g. 'added a further complication'.
(Medicine) A secondary disease or adverse condition developing during the course of, or as a consequence of, another illness, injury, or treatment.
"Pneumonia is a recognised complication of prolonged bed rest."
In clinical writing, 'complication' carries a specific, well-defined meaning distinct from 'side effect'; it usually implies a more serious, disease- or procedure-related outcome.
The plural 'complications' is standard and very common, particularly in medical contexts where multiple secondary conditions may be listed.
"The report listed several potential complications associated with the surgery."
The word 'complication' comes from Latin 'complicare' — literally 'to fold together' — so every complication is, etymologically speaking, life folding itself into a trickier shape.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of complication
Complication derives from the Latin verb 'complicare', meaning 'to fold together' (from 'com-' meaning 'together' plus 'plicare', 'to fold'). The word entered English via French in the early modern period, with the noun attested from around the early seventeenth century. It shares its Latin root with words such as 'complicate', 'duplicate', and 'explicit', all ultimately tracing back to the idea of folding or weaving things into one another.
Related word forms
How complication is actually used
Neutral-to-negative connotation: a complication is almost always something undesirable. In everyday usage it often appears in phrases like 'to complicate matters'. The medical sense is highly established and frequently used in clinical and patient-facing contexts.
Easily confused with complication
Complexity is an inherent state of being intricate or having many interconnected parts, whereas a complication is a specific added problem or obstacle that arises within a situation.
Compliance means conforming to rules or requests, and shares only superficial spelling similarity with complication, which denotes a complicating factor.