Dying is not uniformly painful, and for many people the final hours involve less conscious suffering than we tend to imagine. The experience depends heavily on the underlying cause of death, how far the body’s own protective chemistry has progressed, and what medical interventions are in place. Still, certain types of distress are common in the dying process, and understanding what drives them can make the topic less frightening and help families advocate for better comfort care.
How Organ Failure Generates Pain
When organs begin to shut down, the body enters a cascade of events that can produce real physical discomfort. Tissues deprived of blood and oxygen become ischemic, and damaged cells release a soup of inflammatory signaling molecules. Among these are cytokines, small proteins that coordinate the immune response but also directly sensitize nerve endings. In severe or prolonged illness, the sustained release of certain inflammatory cytokines can cause organ damage and intense pain.1PubMed. Constitutive Inflammatory Cytokine Storm: A Major Threat to Human Health This is one reason why people with advanced cancer, liver failure, or widespread infection sometimes experience escalating pain as the disease progresses.
The kidneys and liver are responsible for clearing waste products and drug metabolites from the blood. As these organs fail, toxins accumulate. That buildup can irritate the nervous system, trigger nausea, and amplify existing pain. It can also change how pain medications work in the body, a complication discussed further below. The point is that organ failure creates a chemical environment in which pain signaling ramps up at exactly the time when the body’s ability to process relief may be declining.
Air Hunger and the Distress of Not Being Able to Breathe
Of all the sensations associated with dying, air hunger may be the most viscerally distressing. It is the feeling that you cannot get enough air, and it is distinct from ordinary shortness of breath. Researchers describe it as a primal sensation, closer in character to the panic of starvation or severe thirst than to ordinary discomfort. Brain imaging studies have shown that air hunger activates the insular cortex, a region that integrates survival-related perceptions including pain and thirst, along with limbic structures tied to anxiety and fear.2PubMed Central. Air Hunger: A Primal Sensation and a Primary Element of Dyspnea Separate imaging work found that the cerebellum is also strongly activated during air hunger, particularly in midline regions associated with the emotional experience of needing to breathe.3PubMed. Neuroimaging evidence implicating cerebellum in the experience of hypercapnia and hunger for air
Air hunger commonly occurs in people dying from heart failure, chronic lung disease, pneumonia, or end-stage cancer that has spread to the lungs. Carbon dioxide builds up in the blood as the lungs lose their ability to exchange gases, and rising COâ‚‚ is one of the strongest triggers for the sensation. Because this feeling activates fear circuitry rather than just pain circuitry, it can be deeply frightening. Opioids, particularly morphine given at low doses, are one of the most effective treatments for easing the sensation, because they dial down the brain’s sensitivity to rising COâ‚‚ levels without necessarily sedating the person into unconsciousness.
Terminal Restlessness
In the final days or hours, some dying people develop a state of agitation that palliative care clinicians call terminal restlessness. It looks alarming from the outside: the person may moan, pull at bedsheets, try to climb out of bed, or appear distressed despite seeming barely conscious. Hospice professionals surveyed about this phenomenon attribute it to a combination of physical causes, including medication toxicity, organ failure, metabolic changes, pain, and difficulty breathing, as well as psychosocial and spiritual distress.4PubMed. Terminal restlessness as perceived by hospice professionals
What makes terminal restlessness hard to interpret is that the person is often unable to communicate. The agitation could reflect genuine pain, or it could reflect confusion, fear, or metabolic derangement that has nothing to do with the conscious experience of suffering. In practice, clinicians treat it as though pain may be present, because the cost of undertreating pain in someone who cannot speak is much higher than the cost of providing comfort medication to someone whose agitation has a non-painful cause. This philosophy of erring on the side of relief shapes much of end-of-life care.
What Dying People Can Still Perceive
One of the questions that haunts families is whether an unresponsive loved one can still hear, feel, or sense what is happening around them. Research suggests the answer, at least for hearing, is yes, possibly until very close to death. A study using brain wave recordings in hospice patients found that most unresponsive people still showed auditory brain responses to changes in tone, and some showed higher-level responses indicating they were processing the meaning of what they heard. Their auditory systems were responding in ways similar to those of healthy, conscious people just hours before death.5PubMed Central. Electrophysiological evidence of preserved hearing at the end of life
This finding carries an uncomfortable implication: if auditory processing is intact, what about pain processing? The honest answer is that we do not know with certainty. Brain wave recordings can tell us that a stimulus was detected but not necessarily whether it was experienced as unpleasant. Still, the fact that sensory systems stay online longer than outward behavior would suggest makes a strong case for continuing pain management even when a person appears to have “checked out.”
Death Rattle Is Probably Not What It Sounds Like
Few sounds at the bedside are as upsetting to families as the death rattle, a gurgling or rattling noise that occurs when secretions pool in the throat of someone too weak to cough or swallow. It sounds like choking or drowning, and it naturally provokes alarm. But the evidence suggests it is far more distressing to the people who hear it than to the person producing it. A systematic review found that death rattle leads to distress in both relatives and professional caregivers, but its impact on patients is unclear, and it is doubtful whether patients suffer from it.6PubMed. Prevalence, impact, and treatment of death rattle: a systematic review A more recent scoping review echoed this, finding a consensus among researchers that death rattle is not distressing to the affected patients, though it may disturb other patients nearby.7PubMed. The Impact of “Death Rattle” on Patients, Informal Caregivers and Healthcare Professionals: A Scoping Review
The reason is likely that by the time the rattle develops, the person has lost the gag reflex and the conscious awareness of having fluid in the airway. The sensation of choking requires a functioning swallow reflex and enough consciousness to register it. Repositioning the person or using gentle suctioning can reduce the sound, but these interventions are primarily for the comfort of family members rather than the patient. Knowing that can ease a great deal of guilt and anguish at the bedside.
The Concept of Total Pain
In the 1960s, Dame Cicely Saunders, widely considered the founder of the modern hospice movement, introduced the idea of “total pain” to describe what dying people actually go through. The concept recognizes that the suffering of someone with an advanced illness is not just physical. It also encompasses psychological distress (fear, anxiety, depression), social pain (isolation, loss of role, burden on loved ones), and spiritual anguish (questions about meaning, regret, fear of what comes next).8PubMed Central. Top Ten Tips Palliative Care Clinicians Should Know About Total Pain
This matters practically because purely physical interventions sometimes fail to relieve a dying person’s distress. A patient receiving adequate doses of morphine for bone pain may still appear tormented if they are grappling with unresolved family conflict or existential terror. Good palliative care teams assess all four dimensions and bring in chaplains, social workers, and counselors alongside physicians and nurses. The concept has become foundational in the field, and it helps explain why some people die peacefully while others with similar medical conditions do not: the non-physical dimensions of suffering can dominate the experience.
How Pain Is Managed in the Final Days
Modern palliative care has a robust pharmacological toolkit. A study of medication use in a palliative care centre found that morphine, midazolam (a sedative), and haloperidol (an antipsychotic used for agitation and nausea) were the three most commonly prescribed drugs. At admission, roughly one in five patients was on morphine. By the day of death, that number had climbed to about nine in ten. Midazolam use rose from about one in ten to nearly six in ten, and haloperidol from about one in four to half of patients.9PubMed Central. Medication use during end-of-life care in a palliative care centre Doses also increased significantly between admission and the final day.
These numbers reflect the reality that as the body fails, more intervention is needed to maintain comfort. The sharp rise in morphine use does not mean all dying people are in agony; it means clinicians are proactively managing pain, air hunger, and distress rather than waiting for a crisis. Midazolam addresses anxiety and restlessness, and haloperidol helps with delirium and nausea, two symptoms that become more common as metabolic waste accumulates.
A harder challenge is assessing pain in someone who can no longer speak or reliably signal their experience. Several tools have been developed specifically for this situation. The Multidimensional Objective Pain Assessment Tool (MOPAT) measures both behavioral cues, such as facial grimacing and body tension, and physiological signs like changes in heart rate. In testing, both subscale scores changed significantly after pain medication was given, suggesting the tool accurately tracks pain levels.10PubMed Central. Assessing pain in nonresponsive hospice patients: development and preliminary testing of the multidimensional objective pain assessment tool (MOPAT) Another validated instrument, the Rotterdam Elderly Pain Observation Scale, has shown promising reliability for pain assessment in non-communicative end-of-life patients.11PubMed Central. The Rotterdam Elderly Pain Observation Scale (REPOS) is reliable and valid for non-communicative end-of-life patients These tools give clinicians a structured way to detect and treat pain in people who cannot advocate for themselves.12PubMed Central. Pain Assessment in Noncommunicative Adult Palliative Care Patients
When Opioids Make Pain Worse
One of the more troubling paradoxes in end-of-life care is that the very drugs used to control pain can sometimes amplify it. Long-term opioid use at escalating doses can produce a state called opioid-induced hyperalgesia, in which the nervous system becomes hypersensitive to painful stimuli as a direct consequence of the opioid therapy itself.13PubMed. Opioid-Induced Tolerance and Hyperalgesia In simple terms, the medicine that was taking the edge off starts making things hurt more.
This is not the same as tolerance, where a steady dose gradually becomes less effective. In hyperalgesia, the pain itself worsens even as the dose goes up. A case report described a hospice patient with metastatic lung cancer who developed extreme skin sensitivity, known as allodynia, following both morphine and hydromorphone. The sensitivity resolved each time the opioid was stopped and the patient was switched to a different medication.14PubMed. Morphine and hydromorphone-induced hyperalgesia in a hospice patient One proposed explanation involves the buildup of active drug metabolites when kidney function declines, which is common in dying patients.
Recognizing this problem is critical because the instinctive response, raising the opioid dose, is the wrong move. Instead, clinicians may rotate to a different opioid, add a non-opioid medication, or turn to newer strategies. Dexmedetomidine, a sedative that works through a completely different pathway than opioids, has emerged as an option for patients with intractable pain or opioid-induced hyperalgesia who might otherwise require deep sedation.15PubMed. Dexmedetomidine: A Novel Strategy for Patients with Intractable Pain, Opioid-Induced Hyperalgesia, or Delirium at the End of Life The fact that alternatives exist is reassuring, but families should know that if a dying person’s pain seems to be getting worse despite increasing medication, it is worth asking the care team whether hyperalgesia could be at play.
The Body’s Own Emergency Pain Relief
The body does not go gently without putting up a chemical defense. Under extreme stress, the brain ramps up production of endorphins, its own opioid-like molecules. These natural painkillers bind to the same receptors that morphine targets, dampening pain signals and producing feelings of calm or even euphoria. Accounts from people who have survived severe injuries often describe a strange numbness or detachment in the immediate aftermath, a phenomenon largely attributed to this endorphin surge.
There is some evidence that conditions commonly associated with dying, such as low oxygen, low blood sugar, and reduced blood flow to the brain, trigger a massive release of the neurotransmitter glutamate. This flood can overactivate certain brain receptors in ways that may produce the dissociative, otherworldly experiences reported in near-death accounts.16Journal of Near-Death Studies. The Ketamine Model of the Near-Death Experience: A Central Role for the N-Methyl-D-Aspartate Receptor Researchers have found that the anesthetic ketamine can reproduce many features of near-death experiences by blocking these same receptors, suggesting the brain may have a built-in mechanism for blunting conscious suffering under extreme physiological threat. Whether this means dying itself feels dreamlike or detached for most people remains unresolvable with current science. But the neurology points to the brain actively working to cushion its own shutdown, not passively registering every insult.
Why Humans Evolved to Feel Pain at All
Given how much pain surrounds dying, it is fair to wonder why pain exists in such intensity in the first place. The evolutionary logic is straightforward: pain keeps organisms alive long enough to reproduce. But the pain that occurs during dying serves no survival purpose. So why does it persist?
One line of thinking is that the pain pathways activated during dying were never selected against because evolution does not optimize for comfortable death. Natural selection acts on traits that affect reproduction, and by the time an organism is dying, its reproductive contribution is typically over. There is no evolutionary pressure to develop a pain-free shutdown sequence.
Research into chronic pain suggests that persistent activity in pain-sensing neurons may have originally evolved to keep injured animals hypervigilant during recovery, reducing their risk of being attacked again while vulnerable.17Trends in Neurosciences. Adaptive mechanisms driving maladaptive pain: how chronic ongoing activity in primary nociceptor can enhance evolutionary fitness after severe injury That hypervigilance is useful when you are healing from a broken leg but meaningless when your organs are failing. The pain system simply has no off switch calibrated to terminal illness. It responds to tissue damage and inflammation the same way whether the damage is recoverable or not. The cruelty of dying in pain is, in a sense, a byproduct of a system that did its job well during the rest of life.
Sudden Death and the Question of Suffering
Not all death involves a slow decline. People who die suddenly from a massive heart attack, a ruptured aneurysm, or a fatal traumatic injury have a very different experience from someone with weeks of progressive organ failure. In many cases of sudden cardiac arrest, consciousness is lost within seconds as blood flow to the brain drops. Whether those seconds involve pain depends on the cause: a heart attack may involve crushing chest pain before the arrest, while a large brain hemorrhage may produce a severe headache that abruptly gives way to unconsciousness. But the window of suffering is narrow compared to a prolonged dying process.
Drowning, suffocation, and other causes that deprive the brain of oxygen likely involve intense air hunger, as described earlier, but consciousness fades relatively quickly once the brain is starved. People resuscitated from drowning often report a transition from panic to calm, which aligns with the endorphin release and glutamate surge that laboratory studies predict. The pattern is consistent: the brain’s emergency chemistry kicks in fast when the threat is acute. It is in slow, chronic dying where pain management becomes the real battleground, because the protective systems that buffer acute crises were not built to sustain relief over days or weeks.