Grieving is a process that naturally follows after every loss. It can be said that loss is a universal thing by which all people are equal. What sets us apart are individual reactions to loss. The psychodynamic factors that influence this process can explain to us in more detail what actually happens in the subconscious of the bereaved after the loss. This paper considers aspects of this process from early childhood to adulthood, with particular emphasis on the psychoanalytic aspect. Although loss can occur in multiple forms, the focus of this paper is on loss in the form of death. At the very beginning, the traditional division in the form of mourning phases is described. In most people, this process takes place without difficulty. However, there are a number of cases in which difficulties arise. The determinants of pathological mourning are described. It describes some of the more significant theories of psychoanalysts who have tried to contribute to understanding the ways in which loss and grief can affect changes in the inner world. In grieving children, due to insufficient emotional-cognitive maturity, it is sometimes difficult to distinguish whether they are grieving or not. Specific reactions of children to loss are described. It is important to notice the differences in relation to adults, so a special part talks about mourning in children. An interesting grieving phenomenon is dealt with, which speaks of the transmission of unprocessed parental traumas to children, who then have to work through the same traumas themselves. At the end of the paper, losses within the context of love relationships are described.