The term “humanitarian crisis” combines two words of controversial meaning and definitions that are often used in very different situations. For example, there is no official definition of “humanitarian crisis” in international humanitarian law. Although some academic disciplines have developed ways of collecting and analyzing data on (potential) crises, all of them have difficulties understanding, defining, and even identifying humanitarian crises. Following an overview of the use of the compound noun “humanitarian crisis,” three perspectives from respectively the disciplines International Humanitarian Law, Public Health, and Humanitarian Studies are discussed in order to explore their different but partly overlapping approaches to (incompletely) defining, representing, and negotiating humanitarian crises. These disciplinary perspectives often paint an incomplete and technocratic picture of crises that is rarely contextualized and, thus, fails to reflect adequately the political causes of crises and the roles of local actors. They center more on defining humanitarian action than on humanitarian crises. They also show four different types of humanitarian action, namely radical, traditional Dunantist, multimandate, and resilience humanitarianism. These humanitarianisms have different strengths and weaknesses in different types of crisis, but none comprehensively and successfully defines humanitarian crises. Finally, a multiperspective and power-sensitive definition of crises, and a more fine-grained language for comprehending the diversity of crises will do more justice to the complexity and longevity of crises and the persons who are surviving—or attempting to survive—them.