Can you really die of a broken heart? The hidden dangers of grief with Mary Frances O'Connor
Psychologist examines the stress that loss has on the body—and how society can help

April 03, 2025

Overview
When we lose someone close to us, we often say we have a broken heart: But what if that’s not just a metaphor?

In her new book, The Grieving Body: How The Stress of Loss Can Be An Opportunity For Healing, Prof. Mary Frances O’Connor, a psychology scholar at the University of Arizona, shares groundbreaking insights into the biological and physiological impacts grief has on our bodies. O’Connor reveals how profound loss can lead to serious medical conditions, from heart attacks to immune system breakdowns, and explains why grieving can make us more vulnerable to diseases like cancer, pneumonia and even autoimmune disorders.

Drawing on her personal experiences and extensive research, O’Connor outlines why our medical system—and society at large—needs to rethink how we support grieving individuals. She makes a powerful case for viewing grief not only as an emotional experience but as a medical event deserving careful monitoring and intervention, similar to pregnancy or chronic illness.

Related
Why taking our grief out into nature can help us heal — New Scientist
What Happens To Your Body When You’re Grieving — Science Friday
The nights are hard — The British Psychological Society
‘The Grieving Body’: Mary-Frances O’Connor talks about her new book — Tucson Weekly
Transcript
Paul Rand: When we lose a loved one, we say we have a broken heart or feel deep pain, but are those expressions just figures of speech?

Mary-Frances O’Connor: I think for most people they associate grief with sadness, but people don’t generally know that grief is a physiological response. It’s certainly how people describe their grief in very physical terms, “My broken heart,” or the pangs of grief as a physical sensation they’re describing.

Paul Rand: But what if the way we feel grief and the actual biological experience are more connected than we think?

Mary-Frances O’Connor: In scientific research, we can see the physiological response. Then I think the thing I have found most compelling is that we see the medical outcomes when we have loss as humans.

Paul Rand: That’s Mary-Frances O’Connor, a professor of psychology at the University of Arizona, where she also directs the Grief, Loss and Social Stress Lab. She’s written many books on grief, and her latest is called the Grieving Body, How The Stress of Loss Can Be an Opportunity for Healing.

Mary Frances O'Connor
Mary-Frances O’Connor: I think that people are really hungry to understand scientifically what’s happening with people, so they want to understand what are people going through, but also why?

Paul Rand: As it turns out, grief can physically impact our body in all sorts of ways from our immune system to stress hormones.

Mary-Frances O’Connor: The chronic stress that we find co-occurs with prolonged grief is associated with longer term illnesses. Grief can be very stressful or loss can be very stressful, but dealing with that grief is very stressful often for our body.

Paul Rand: Things like cardiac health, disease, resistance, even cancer can be exacerbated by grief.

Mary-Frances O’Connor: One of the things that science can give us are the theories as to not just what’s happening, but how is this happening in the body and therefore what might we do? Those kinds of questions.

Paul Rand: O’Connor believes that understanding what happens to someone who is grieving should lead us to think about how to better support them.

Mary-Frances O’Connor: There’s all sorts of policies that become very important as we think about how do we want to support people who are grieving in our country?

Paul Rand: From the University of Chicago Podcast Network, welcome to Big Brains, the show where we explore the groundbreaking research and discoveries that are transforming our world. I’m your host, Paul Rand. Join me as we meet the minds behind the breakthroughs, the science of how grief impacts our body and what can our body teach us about how to heal.

Paul Rand: The University of Chicago Leadership and Society Initiative guides accomplished executive leaders in transitioning from their long-standing careers into purposeful encore chapters of Leadership for society. The initiative is currently accepting candidates for its second cohort of fellows. Your next chapter matters for you and for society. Learn more about this unique fellowship experience at leadforsociety.uchicago.edu. For years, O’Connor studied the intricate ways that humans process grief, but she didn’t fully realize how grief impacts the body until it happened to her.

Mary-Frances O’Connor: I was quite young when my mom died. I was 26. Not as young as some people, unfortunately, when they lose a parent, but really at that point in my life, I was in graduate school. I hadn’t really spent a lot of time in my body, so to speak. My body was there to carry my head around, and so in my grief, I was just ricocheting through my life. I was just staying busy and doing the things I thought I was supposed to do.

Paul Rand: Shortly after her mom passed, O’Connor found out that she had MS.

Mary-Frances O’Connor: In my family, we have a history of multiple sclerosis, but we can’t overlook the idea that my symptoms emerged in the context of the stressful experience of my mom dying and the grief that I was having.

Paul Rand: O’Connor is very clear that her grief didn’t cause her MS, but the cascade of negative effects that grief has on our bodies can exacerbate underlying problems and bring them to the surface.

Mary-Frances O’Connor: The reason I think that’s important is, each of us carries different predispositions. We each have a family history of something. And so, thinking about the idea that bereavement may be a stressful time that reveals something that might’ve occurred anyway, but to know that this is a risky time helps us to think about, “Ah, I should take these seriously, these symptoms, I should follow up with medical professionals to see what’s going on.” But not all of the physical symptoms that we experience during bereavement are an indication that something is broken.

Paul Rand: But even if you don’t have negative health predispositions, the research does seem clear that grief really can generate all sorts of physical problems on its own.

Mary-Frances O’Connor: It turns out we see increased all-cause morbidity and mortality. Morbidity is getting a diagnosis of some medical illness, and of course, we know what mortality is. But all-cause means that we see increased risk for all types of illness from pneumonia to COPD to colon cancer.

Paul Rand: Okay. You talked about this idea of dying of a broken heart, and there’s some real data behind all this. What does it mean, to die of a broken heart?

The Grieving Body book cover
The Grieving Body
Mary-Frances O’Connor: A man is almost twice as likely to die of a heart attack in the first three months after his wife dies compared to a married man is a stunning medical statistic. That really helps us to see, “Oh, this is a physiological response, as well as an emotional one.” This statistic that I gave you comes from a number of different very large scale epidemiological studies.

Paul Rand: But what exactly is happening here biologically? Well, one answer may come from a massive study done in Australia that showed grieving people have higher heart rates and higher blood pressure with lower variability.

Mary-Frances O’Connor: We also have a study that says, on the day a loved one dies, you are 21 times more likely to have a heart attack than any other day of your life.

Paul Rand: Holy cow. Okay. Wow.

Mary-Frances O’Connor: Isn’t that crazy?

Paul Rand: It is.

Mary-Frances O’Connor: We know that this is a replicated fact that we see increased mortality after the death of a loved one.

Paul Rand: O’Connor has done her own research in this area. In one study, she asked participants to think about their feelings of grief over a loved one while they were at the same time hooked up to a blood pressure monitor. Stunningly, on average their blood pressure, increased levels normally seen during moderate exercise, even though the subjects were simply sitting still.

Mary-Frances O’Connor: Now, the risk goes down day by day then although remains elevated for a few months,

Paul Rand: But it’s not just heart attacks that are a medical concern. Large studies also show increased rates of cancer and respiratory disease, and some studies have even shown that people who are grieving are more susceptible to pneumonia and influenza.

Mary-Frances O’Connor: The thing that’s important is thinking about, well, what mechanisms could account for that? We think of the organ systems as all having different processes. How could something like the death of a loved one be affecting all of those systems?

Paul Rand: What’s going on here?

Mary-Frances O’Connor: I will say, we are at the very beginning of understanding the connection here between more intense psychological grief experiences and worse medical outcomes. The reason is that most of my colleagues either study the psychological effect or they study the medical effect. We don’t actually have a lot of researchers yet really brought those together.

Paul Rand: But we can do some things. O’Connor and her colleagues have found a wealth of evidence that grief hurts our body through two systems, our immune system and our stress system.

Mary-Frances O’Connor: In my own research, what I’ve seen is when we start to think about the idea that our endocrine system, our hormones like stress hormones, like cortisol and our immune system, things like inflammation, that if those are increased in bereavement, which we see in the data, then that’s going to affect every organ. Inflammation is going to make your joints hurt more if you have rheumatoid arthritis, and it’s going to make it harder to breathe if you have asthma. They’re both inflammation, but they can be affecting all these different systems, which is what we see in the data.

Paul Rand: Talk to us a little bit about this idea of inflammation when the body is grieving and how does that occur, and what studies are pulling this apart?

Mary-Frances O’Connor: Inflammation is a natural immune response. We need inflammation, because the markers, the proteins that make up inflammation, the cytokines, are really our communication messengers between immune cells. They’re the ways that immune cells say, “Hey, I need more help over here. Can I get some more immune cells over where I am?” The way they send that message is they send these proteins out in the form of inflammation markers. Now that’s a natural process. When the immune system then has the response that it needs, those inflammation markers stop being produced. There’s a natural way in which the immune system responds when it needs help and then recovers when that issue is over. Unfortunately, we have a couple of situations that can happen in bereavement that send that system a little askew. One of them is that if we continue to have very intense, prolonged frequent waves of grief, this then becomes a more chronic stressor.

Paul Rand: This becomes a compounding problem. Inflammation affects our body’s ability to produce serotonin, which regulates our mood. When it’s not available, we often feel anxious or depressed. While our grief may be causing our inflammation, the inflammation in turn may be exacerbating our grief. It’s a vicious cycle that’s difficult to break.

Mary-Frances O’Connor: Learning how to manage our natural waves of grief, figuring out what does help to calm or soothe us can also help our body to relax and restore when a wave of grief has ended. In addition, sometimes the system gets cranked up. The immune system gets turned on in the sense of we’re making lots of inflammation. We may be predisposed to make one type of immune cell over other types of immune cells, and if we get in this stuck state where the immune system is very activated, that can lead to then other issues around autoimmune disorders or allergic reactions and so forth. The other chronic issue that we’re trying to stay out of is where the system gets outside the bounds of where the immune system is supposed to be resiliently responding, and that’s what we worry about if the grief becomes more chronic, or if people don’t develop a good toolkit of how to help themselves find comfort and relaxation, even in the midst of grief.

The Grieving Brain
The Grieving Brain
Paul Rand: When we can’t find a way to relax our body, our cortisol levels can increase. This is the second piece of the puzzle of how grief causes bodily harm.

Mary-Frances O’Connor: Cortisol determines whether we’re going to use up glucose or whether we’re going to store it, for example. In a stressful situation where our body recognizes, “Oh, lots of demands, more cortisol,” it will do that in grief, it will do that in other stressful contexts. But we know, for example, that the death of a loved one is ranked as the highest stress that human beings experience. It is just one of many stresses, but it’s also a very intense version.

Paul Rand: In one study, researchers found that participants who had acute grief had higher cortisol levels, and cortisol controls so many things that are important, our metabolism, regulating blood sugar, how much energy goes to our muscles and brain. It also controls our sleep-wake cycle.

Mary-Frances O’Connor: Our body is trying to manage the demands of the world physiologically. Lisa Feldman Barrett describes, “We have a body budget. We have all the food that we take in, all the resources that we take in. We then have an opportunity to use those in forms of work and activity and so forth.” Cortisol is a big determiner of that body budget. Now, the way psychologists think about stress is actually... You know the old timey balance scales like you might see in the old West where you put gold right on one side and then you put weights on the other side to see how much it weighs? That’s what the image that I have when I think of stress. The reason is stress is defined as when we perceive that our demands in the world are more than the resources that we have to do with those demands.

Mary-Frances O’Connor: When the scale is tipped, that is the state of stress when it’s out of balance, so things we can do about that are possibly to increase the resources that we might have. What are other ways that we might address the demands of the world? A different way to think about stress is to reduce the demands on ourselves. Many people find they can’t work as effectively, or they need to step back from volunteer opportunities in their life or other things. They need a little extra time and space to pay attention to what’s happening to them so that they can bring this balance scale back into alignment.

Paul Rand: When we’re in a state of grief, how do we get those scales back into alignment? Well, that’s after the break. If you’re getting a lot out of the important research that’s shared on Big Brains, there’s another University of Chicago Podcast Network show that you should check out. It’s called Capitalisn’t. Capitalisn’t uses the latest economic thinking to zero in on the ways that capitalism is and more often isn’t working today. From the debate over how to distribute a vaccine to the morality of a wealth tax, Capitalisn’t clearly explains how capitalism can go wrong and what we can do about it. Listen to Capitalisn’t, part of the University of Chicago Podcast Network. On the flip side of this, interestingly, you talked actually, there can be opportunities for healing when grief is there. Explain that if you could.

Mary-Frances O’Connor: I used the word opportunity, although it’s not something I would wish on anyone, but this is the reason I said it that way. When we’re grieving, when someone who is so important to us has died, it’s like the volume gets turned up on our emotions, on our responses. With the volume dial turned up like that, sometimes we can access our experience more easily.

Mary-Frances O’Connor: In my own case, what I came to realize was that I had to find new ways to respond to some of my physiological symptoms. I had to find new ways to respond to feeling lonely, or I had to find new ways to respond to the physical pains that I had in my hands and arms. That because they’re so intrusive in a weird way, it gave you an opportunity to learn, “Oh, this is what helps,” or, “This is what doesn’t really help.” There’s a certain authenticity in that, in knowing, “Oh, this is how I respond in grief, and this is what I can do to actually help with that.” That is then something that you take through the rest of your life when you’re responding to other types of stressors or other types of losses, because you know yourself really well.

Paul Rand: Correct me if I’m wrong on this, but I would imagine that people have a better time accepting grief in themselves if it’s for a human, whereas they might question it more if it’s for a pet or something else that is not human-related, but the stresses and the grieving can be the same.

Mary-Frances O’Connor: It’s interesting. In psychology, we have a term for this. We call it disenfranchised grief. Disenfranchised grief means this is something you’re grieving that your social network doesn’t understand to be a loss. Many of us, if we have lost a pet and we’re around people who have not had that relationship with a pet, they just don’t get it. But this happens in other ways as well. A classic example is if an ex-husband or an ex-wife dies, that can cause a great deal of grief for people, but the people around them may think, “Well, but you divorced them. Why are you having grief over this?” But they still were a person in your life who at one time, I would always be there for you and you would always be there for me. These types of disenfranchised grief can be difficult, not just because we have to deal with the grief part, but we also have to deal with the misunderstanding of what we’re going through.

Paul Rand: It’s not just the misunderstanding of our peers that O’Connor is concerned about. She has her sights set on the medical establishment.

Mary-Frances O’Connor: The fact that this data has been around for so long, when we know there’s a medical risk, usually we’re creating ways to buffer that risk or to assess the risk and intervene if needed. Knowing this data has actually been around for a long time, the real trouble I see is, why are we not trying to do anything? That’s my question.

Paul Rand: If we know that grief can wreak havoc on our bodies, shouldn’t we be treating it like an underlying condition?

Mary-Frances O’Connor: I sometimes think of pregnancy and bereavement as having some similarities. What I mean by that is that pregnancy is a totally natural normal process. Pregnancy is not a disease. It’s still a very physiological event. What we’ve done as a society is because we recognize that it’s also a heightened time for medical risk, is that we have supports in place, prenatal care, where we provide education for people about what the experience should be like, and then we have opportunities for them to check in so that we can see if they’re having gestational diabetes or hypertension and provide appropriate medical responses in those instances. I think there’s ways to think about whether our healthcare could consider bereavement in a similar way. This is a risky time for people, most people will do fine, but we need to have both education, literacy and also a way for them to check in and see if they’re doing okay and follow up if they’re not.

Paul Rand: Okay. You’re talking about the studying of this an educational setting. Are medical professionals trained in the idea in a way that you think is sufficient to understand grieving and bereavement, and not only the impact on the body, but ways to help people work through it?

Mary-Frances O’Connor: Unfortunately, none of our helping professions are receiving the type of training and grieving that is most current in our scientific understanding, and frankly, often none at all. I really would love to see that. I trained as a psychologist, clinical psychologist, great graduate program I went to had exactly zero lectures on grief. That is true for psychiatry. That is true for medical doctors. They will have-

Paul Rand: Why do you think that is?

Mary-Frances O’Connor: Well, it’s interesting. There’s been a real taboo about talking about grief in part, because it leads to talking about death. Death is not something that our medical professionals like to talk about, as you might imagine. But in addition, I think there is a misunderstanding. We need to get the word out, so to speak. Most people think about Elizabeth Kubler-Ross’s five stages of grief, which came out in 1969. Think how far science has come and medical training since 1969. Our curriculum is not updated to include much of what we know now about how to address grief and grieving. Those five stages are not something that we think of as happening in a prescribed order and certainly not coming to a closure where grief ends. Those have not been borne out in longitudinal studies. I think it’s important to improve grief literacy among all the helping professions would really advance our ability to support grieving people.

Paul Rand: Could a wider understanding of the negative health effects of grief actually change national policies?

Mary-Frances O’Connor: I find that there are many areas of policy that I’ve only really just begun to put my toe into, because in those areas, people want evidence-based answers in order to make good decisions like, is two days sufficient for bereavement leave? Or how do we keep an undergraduate at our university enrolled in school when they’ve had the death of a parent? Or should we be thinking about the way that social security automatically reaches out to children when a parent has died to provide those resources that we know are important to supporting something during a developmentally important period so they can go on to be happy, healthy, productive adults? There’s all sorts of policies that become very important as we think about how do we want to support people who are grieving in our country?

Paul Rand: I have a better understanding of grief. I have sense of the symptoms. Now we’re at this part of your work where you actually give people some counsel on what they could or should be doing to help themselves through the grieving process. Let’s go into that a little bit if we can.

Mary-Frances O’Connor: I think the first thing to say is that you walk into the room when a loved one dies with the body that you have, so each person is going to react differently based on their relationship with this person, their own history with grieving, their own physiological predispositions. I say that because much of what I study is grief on average. I’m studying it at a group level. I think of this a little bit like lending you my glasses. My glasses might help bring something into focus you hadn’t thought of before, but they’re probably not the right prescription for you, so take the things that I say that make sense to you and ignore the parts that don’t work. Having said that, I think that many of us are afraid of our grief response, and we avoid situations that might cause us to feel the painful waves of grief, or we try to avoid thoughts, or we try to avoid conversations. We know now that some of this avoidance can really get in the way.

Mary-Frances O’Connor: I think of grieving as a form of learning. We have to learn what does it mean to walk through this world without my partner or my daughter or my best friend or my boss? What does it mean to be in the world when they’re not here, when they were supposed to be here? That is a learning process then, and the things that get in the way of learning often get in the way of grieving. If we’re avoiding going to class, if we’re avoiding reading the textbook, we’re probably not going to learn very much. It takes great courage to put ourselves into situations that are going to feel difficult, but it’s also the way that our brain can understand what’s happening now, and to find the positive and the negative in those moments. Avoidance is something I really can encourage people to just consider, is there something you’re avoiding? If so, why? And how else might you approach that thing?

Paul Rand: Every society, I imagine, has their own ways of understanding and dealing with grieving. You talked earlier about thinking about this bereavement period as a medical risk factor. How do we do in this country with thinking about it that way, and how does that compare to others that you think do it more progressively?

Mary-Frances O’Connor: Well, it’s interesting. The experience of grief is universal. It happens in all cultures across all times of history. To some degree, even in other social mammals, we see evidence of grief behaviors. But what is interesting is although the experience is clearly universal, the expression of our grief varies widely. Enormous differences in how we express grief and in how cultures support grieving people. Now, a very interesting cross-cultural study done quite some time ago now, where there were psychologists from the People’s Republic of China who were collaborating with American psychologists, what they found was it didn’t actually matter so much how much grief was expressed by individuals, but when the amount of grief that they expressed was a mismatch for what their culture expected them to express, either too much or too little, it was in cases of mismatch that people really struggled to adapt.

Paul Rand: Interesting, you think too little could be one of those too.

Mary-Frances O’Connor: Yes. Isn’t that interesting? What that means to me is that we can think about the idea that, in many ways, when we grieve a loved one, we are not the only person who experienced that death. To some degree, although it can feel like a very personal experience, we’re also coming to understand the meaning of that loss as a family or a neighborhood or a workplace.

Paul Rand: The other side of this is, when people are grieving, people around them don’t know how to interact with them. How do you counsel on that?

Mary-Frances O’Connor: It’s funny, I am not a social media person, but when books come out, I spend a little time on social media trying to help people to come across the book. I see a lot on social media about the things you’re supposed to say and not say to people who are grieving. I find that difficult, because in my experience, what makes sense to one person just doesn’t make sense to another. It’s really about getting to know what would be supportive to this specific person in front of me who’s grieving. For example, I often see, “You should never tell someone that their loved one is in a better place.”

Paul Rand: Yes, yes. I was just thinking of that.

Mary-Frances O’Connor: If I don’t know this person, or I’m talking to someone my age or younger, I’m probably not going to say that. But I can tell you for my parents’ generation, when I see my aunts and uncles at funerals, that is the thing that brings them great comfort.

Paul Rand: Oh, gosh. Okay.

Mary-Frances O’Connor: Right, because it fits with their understanding of what’s happening, this person is in a better place in their mind, in their world. To reflect on that together with them brings great comfort. Death is part of life. Loss is something we will all experience. When we go through it, if we have the resources at the time, we end up developing an understanding of how life works that is richer and more accurate. We come to understand the agility of life. We come to understand that our loved ones won’t be with us forever. As difficult as that is to understand, if we know that at a very deep level, it probably changes the decisions we make, how we choose to spend our time, how we savor experiences with our living loved ones.

Mary-Frances O’Connor: I think there’s a way in which if a person has the resources to develop an understanding that is meaningful out of a loss experience, then they often go on to have this greater understanding of the world of themselves, greater empathy and understanding of the people around them. Now, if they don’t have the resources, they can come away with core beliefs about the world as an unsafe place, or I’m not worthy of being loved, and those are problematic, those are some things we need to provide resources so that doesn’t happen. For example, making sure no one grieves alone. But given that there is this long-term growth that can happen with grieving, it seems perhaps not the right track to short-circuit that if what we’re trying to do is mask a painful experience.

Matt Hodapp: Big Brains is a production of the University of Chicago Podcast Network. We’re sponsored by the Graham School. Are you a lifelong learner with an insatiable curiosity? Access more than 50 open enrollment courses every quarter. Learn more at grahamm.uchicago.edu/bigbrains. If you like what you heard on our podcast, please leave us a rating and review. The show is hosted by Paul M. Rand, and produced by Lea Ceasrine and me, Matt Hodapp. Thanks for listening.

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