Ambiguous loss is a type of grief that occurs when someone you love is lost to you, but without the finality that death provides. The person is either physically gone without confirmation of what happened to them, or physically present but no longer the person you knew. Psychologist Pauline Boss coined the term in the 1970s to describe this particular kind of suffering, which resists the normal process of mourning because there is no clear endpoint, no confirmation, and often no social recognition that a loss has occurred at all.
The Two Types of Ambiguous Loss
Boss identified two distinct forms, each defined by which dimension of the person is missing.
The first type involves physical absence with psychological presence. The person is gone, but there’s no proof of death, no body, no certainty. This includes soldiers missing in action, people who disappeared during political conflicts, children who were kidnapped, and individuals unaccounted for after disasters like the September 11 attacks. Immigration can trigger it too: a family member moves to another country and contact fades, but they’re still alive somewhere. You carry this person in your mind and heart while living in a world where they are simply not there.
The second type is the reverse: physical presence with psychological absence. The person is still alive, still in front of you, but the relationship you had with them is gone or fundamentally changed. Dementia is the most commonly cited example. Your parent sits across the table but no longer recognizes you. Other situations that trigger this form include addiction, traumatic brain injury, severe mental illness, estrangement, and incarceration. The person exists, but the connection that defined your relationship has eroded or vanished. Mayo Clinic Health System describes this as “goodbye without leaving,” noting that it can result from your own decisions or be entirely outside your control.
Why It’s Harder Than Ordinary Grief
When someone dies, grief is brutal but has a structure. There is a funeral, a date, a shared understanding that the person is gone. Ambiguous loss offers none of that. The uncertainty blocks the grieving process because your brain can’t fully commit to mourning someone who might still return, or who is sitting right next to you. Traditional grief therapy, which helps people move through loss toward acceptance, doesn’t work here because there is nothing definitive to accept.
This creates what researchers call “frozen grief.” Families get stuck. They can’t reorganize roles, make major decisions, or move forward because doing so feels like giving up on someone who might still come back, or like betraying a person who is technically still present. A mother whose child went missing 10 years ago may keep the bedroom exactly as it was. A wife whose husband has advanced dementia may resist any suggestion that she build a social life without him, because he’s not dead.
The lack of social recognition compounds the pain. Friends and extended family often don’t understand why someone is grieving a person who is “still alive,” or why they can’t simply “move on” from someone who disappeared years ago. There are no sympathy cards for this kind of loss, no bereavement leave, no cultural rituals. The grief is real but invisible.
The Toll on Caregivers
The impact on dementia caregivers illustrates how damaging ambiguous loss can be over time. Roughly 17% of primary caregivers experience clinically significant grief before the person with dementia has even died, and about 40% of spouses caring for someone with dementia meet the criteria for clinical depression, compared to only 5% among spouses of elderly people without the condition. These numbers reflect years spent watching someone disappear in slow motion while continuing to provide daily physical care for their body.
This kind of prolonged, unresolved stress affects more than mood. Caregivers dealing with ambiguous loss often experience sleep disruption, social isolation, and a persistent sense of guilt for feeling grief about someone who is still breathing. The loss repeats itself in small ways every day: a blank look where recognition used to be, a conversation that no longer makes sense, a personality that has shifted beyond recognition.
Both/And Thinking as a Way Forward
Because closure is not available, Boss and her colleagues developed a different approach. Rather than pushing toward resolution, the goal is building enough resilience to live well alongside a loss that will likely never be resolved. The central strategy is called “both/and thinking,” which means learning to hold two contradictory ideas at the same time. He may be dead, and he may not be. She is still here, and she is also gone. As Boss puts it, this is as close to the truth as people with ambiguous losses can get.
In practice, both/and thinking means you stop waiting for certainty before you allow yourself to grieve, to reorganize your life, or to find meaning again. You acknowledge the loss without abandoning hope. You can keep a missing person in your heart while also building new routines that don’t depend on their return. You can love someone with dementia deeply while also mourning the relationship you used to have with them. One of Boss’s colleagues described the core message this way: you can hold “yes, he may be here” and “yes, he isn’t” and still be comfortable having a life with meaning.
This is not the same as “getting over it.” It’s a shift from either/or thinking, which demands a verdict, to a more flexible stance that matches the reality of the situation. The loss remains. What changes is your relationship to the uncertainty, and your willingness to live fully even without answers.
Situations That Trigger Ambiguous Loss
The concept applies far more broadly than most people initially realize. Beyond dementia and missing persons, ambiguous loss shows up in divorce (the co-parent is alive but the partnership is gone), infertility (grieving a child who was imagined but never existed), adoption (for both birth parents and adoptees navigating identity), chronic illness that changes someone’s personality or capacity, and even major life transitions like immigration, where you lose a homeland, a culture, and a version of yourself without anyone dying.
Boss’s original research examined military families and the relatives of political “desaparecidos,” people who vanished during civil conflicts in Argentina, Chile, Colombia, and other countries. The framework has since been applied to families affected by ethnic cleansing in Kosovo and Rwanda, and to communities after large-scale disasters where remains were never recovered. In all of these contexts, the same mechanism is at work: loss without verification, grief without permission, and a future that can’t fully begin because the past won’t close.
Naming the experience matters. Many people living with ambiguous loss spend years feeling that something is deeply wrong but lacking the language to describe it. Learning that this form of grief has a name, a research base, and a set of tools designed specifically for it can itself be a turning point. It validates what you already knew: that this is real loss, even if no one has died.