National Institute of Mental Health
Grief may be triggered by the death of a loved one. People also can experience grief if they have an illness for which there is no cure, or a chronic condition that affects their quality of life. The end of a significant relationship may also cause grieving.
Everyone feels grief in their own way. But there are common stages to the process of mourning. It starts with recognizing a loss and continues until a person eventually accepts that loss. People’s responses to grief will be different, depending on the circumstances of the death. For example, if the person who died had a chronic illness, the death may have been expected. The end of the person’s suffering might even have come as a relief. If the death was accidental or violent, coming to a stage of acceptance might take longer.