A crisis (from the Greek κρίσις - krisis; plural: "crises"; adjectival form: "critical") is any particular event that is (or is expected to) lead to an unstable and dangerous situation affecting an individual, group, community, or whole society. Crises are deemed to be negative changes in the security, economic, political, societal, or environmental affairs, especially when they occur abruptly, with little or no warning. More loosely, it is a term meaning "a testing time" or an "emergency event".
Crisis is often linked to the concept of stress. In occidental culture, the term is often used to suggest a negative or fraught experience while in UK as a hazardous event and in oriental cultures like China it means danger and opportunity (Chinese characters used are Wei and Chi). In general crisis is the situation of a complex system (family, economy, society) when the system functions poorly, an immediate decision is necessary, but the causes of the dysfunction are not immediately identified.
Crisis has several defining characteristics. Seeger, Sellnow, and Ulmer say that crises have four defining characteristics that are "specific, unexpected, and non-routine events or series of events that [create] high levels of uncertainty and threat or perceived threat to an organization's high priority goals." Thus the first three characteristics are that the event is
Apart from natural crises that are inherently unpredictable (volcanic eruptions, tsunami etc.) most of the crises that we face are created by man. Hence the requirements of their being 'unexpected' depends upon man failing to note the onset of crisis conditions. Some of our inability to recognise crises before they become dangerous is due to denial and other psychological responses that provide succour and protection for our emotions.