What you feel during an overdose depends almost entirely on what substance is involved, how much was taken, and how your body responds in the minutes that follow. An opioid overdose typically pulls a person into deep sedation and slowed breathing, often so quickly that the person loses awareness before registering much of anything. A stimulant overdose is closer to the opposite: racing heart, crushing chest pain, and overwhelming panic. The experience is not one thing, and the aftermath, including what happens when someone is revived, brings its own set of sensations that survivors describe as intensely distressing.
Opioid Overdose and the Slide Into Unconsciousness
Opioids like heroin, fentanyl, and prescription painkillers produce overdoses that follow a fairly consistent pattern. The person becomes heavily sedated, breathing slows and turns shallow, pupils shrink to pinpoints, and mental awareness fades. In clinical terms, the overdose is defined by depressed mental status, slow and shallow breathing, and constricted pupils, and if untreated the resulting oxygen deprivation can lead to cardiac arrest and death.1PubMed Central. Neurocognitive impairments and brain abnormalities resulting from opioid-related overdoses: A systematic review
From the inside, many survivors report that the experience was not painful in the moment. Opioids suppress pain signals and create euphoria at high doses, so the transition from a dangerous high to an overdose can feel like falling asleep or drifting away. Some people remember nothing at all between taking the drug and waking up, sometimes hours later, sometimes in an ambulance. That blank gap is itself a clue to how quickly opioid overdose overwhelms consciousness. You are not lying there aware that you are dying. You are, for all practical purposes, gone.
The danger in that deceptive calm is what makes opioid overdoses so lethal. Because the person is not thrashing or screaming, bystanders sometimes assume they are just sleeping heavily. Meanwhile, oxygen levels in the brain are dropping. If breathing slows enough or stops entirely, the brain starts suffering damage within minutes.
Stimulant Overdose Feels Like the Body Turning Against Itself
Cocaine, methamphetamine, and other stimulants produce an overdose experience that could not be more different from opioids. Instead of sedation, the body goes into a state of dangerous overactivation. Symptoms include chest pains, overheating, extreme anxiety or panic, dizziness, confusion, hallucinations, psychosis, nausea, jerking or rigid limbs, dangerously fast heart rate, and spiking blood pressure.2PubMed Central. Characterizing and Responding to Stimulant Overdoses: Findings from a Mixed Methods Study of People who Use Cocaine and Other Stimulants in New England
Unlike an opioid overdose, you are often acutely aware that something is terribly wrong. Your heart pounds so hard you can feel it in your throat. Body temperature climbs, sometimes to the point of heat stroke. The psychological dimension is just as brutal: paranoia, a sense of impending doom, and in severe cases full-blown psychosis where the person cannot distinguish hallucinations from reality. Some people describe feeling certain they are about to die, and being unable to do anything about it.
There is no naloxone equivalent for stimulant overdose. Emergency treatment is supportive, meaning clinicians work to control individual symptoms like seizures, dangerously high blood pressure, or hyperthermia. That means the person experiencing a stimulant overdose may endure the full onslaught of symptoms until the drug clears their system or until emergency care can bring the body back under control.
Sedative and Benzodiazepine Overdose
Benzodiazepines like alprazolam (Xanax) and lorazepam (Ativan) are prescribed for anxiety and insomnia, but in overdose they produce a deep, potentially dangerous level of sedation. A case report described a patient who overdosed on both alprazolam and lorazepam at many times the normal blood concentrations. She was unresponsive, hypothermic, and breathing rapidly but shallowly, with pinpoint pupils and absent brainstem reflexes, a state so severe it mimicked structural brain damage.3BMJ Case Reports. Alprazolam and lorazepam overdose and the absence of brainstem reflexes
In practice, benzodiazepine overdoses taken alone are less likely to be fatal than opioid overdoses, but they are rarely taken alone. When mixed with opioids or alcohol, the sedative effects stack, and breathing can stop. From the perspective of the person overdosing, the experience is similar to opioid overdose in the sense that consciousness fades rapidly. The person may remember feeling extremely drowsy or confused just before blacking out, and often has no memory of the hours that follow.
Among elderly patients, sedative overdoses present a particular concern. A study of drug poisoning in older adults found that patients who had accidentally overdosed on sedatives were far more likely to need hospitalization and stayed nearly twice as long as those who overdosed intentionally, in part because their bodies cleared the drugs more slowly.4PubMed Central. Intentional or unintentional drug poisoning in elderly people: retrospective observational study in a tertiary care hospital in Japan For older adults, even a modest accidental excess of a prescription sedative can produce prolonged unconsciousness and confusion that younger people might recover from more quickly.
Substances You Might Not Expect
Overdose is not limited to “hard drugs.” Over-the-counter medications and newer synthetic substances produce their own distinctive and sometimes bizarre overdose experiences.
Aspirin, for example, is a salicylate, and at toxic blood levels it can cause sudden hearing loss and ringing in the ears (tinnitus).5PubMed Central. A case of bilateral sudden hearing loss and tinnitus after salicylate intoxication People experiencing salicylate poisoning also commonly report nausea, vomiting, rapid breathing, and confusion. The hearing symptoms are distinctive enough that sudden tinnitus after taking large amounts of aspirin should be treated as a warning sign. In most cases, salicylate-induced hearing loss is reversible once the drug clears the body, but not always.
Synthetic cannabinoids, sometimes sold as “Spice” or “K2,” produce overdose experiences markedly different from natural cannabis. These lab-made compounds bind far more powerfully to the same brain receptors, and overdose can trigger full psychotic episodes with paranoia, agitation, hallucinations, and disorganized thinking.6PubMed Central. Synthetic Cannabinoids-“Spice” Can Induce a Psychosis: A Brief Review Users sometimes describe the feeling as losing control of their own mind, experiencing terrifying visual or auditory hallucinations, or being unable to recognize where they are. The psychosis can persist for hours or, in some cases, trigger longer-term psychiatric symptoms.
Stimulant overdoses can also produce tactile hallucinations, a sensation called formication. The person feels as though insects are crawling on or beneath the skin, and the sensation is vivid enough that people may scratch themselves raw trying to get rid of bugs that are not there. One case described a teenager admitted to a toxicology unit with amphetamine overdose who was diagnosed with Ekbom’s syndrome, the clinical name for delusional parasitosis driven by stimulant toxicity.7Asia Pacific Journal of Medical Toxicology. Misdiagnosed Pruritus; Formication due to Chronic Amphetamine Abuse It is one of the more disturbing sensory experiences an overdose can produce.
What Waking Up After Naloxone Feels Like
For opioid overdoses, naloxone (brand name Narcan) is a lifesaving reversal agent. It works by knocking opioids off the brain’s receptors, effectively ending both the overdose and the high at the same time. For the person being revived, this transition is often extremely unpleasant.
A qualitative study of people who use opioids in New York City identified three broad categories of experience after naloxone reversal. Some people wake up in a state of intense rage, with hostile and aggressive outbursts. Others go straight into opioid withdrawal, which means muscle aches, nausea, sweating, and severe agitation within minutes. A third group experiences milder reactions like temporary amnesia, emotional outbursts, or general physical discomfort.8International Journal of Drug Policy. Opioid overdose reversals using naloxone in New York City by people who use opioids: Implications for public health and overdose harm reduction approaches from a qualitative study
The rage response is particularly notable because it can endanger the very people who just saved someone’s life. People waking from naloxone reversal sometimes lash out physically at bystanders or paramedics. This is not a voluntary or rational response. The brain goes from a state of near-death sedation to acute withdrawal in seconds, and the result can be explosive. Understanding this pattern matters for anyone who might administer naloxone to a friend or stranger, because the person you revive may not be grateful in the immediate aftermath.
A separate study of overdose survivors found that many described intense physical pain and emotional distress immediately following reversal, and that this distress reduced their willingness to engage with medical providers or accept further help.9International Journal of Drug Policy. Building connection: overdose survivors’ and professional service providers’ perspectives on immediate post-overdose care Some survivors also reported experiencing disrespect and stigma from the people who responded to their overdose, compounding an already traumatic experience.
Physical Damage That Outlasts the Event
Even when someone survives an overdose, the body may sustain injuries that produce symptoms for weeks or longer. The most serious of these is brain damage from oxygen deprivation. Opioid-induced respiratory depression can cause prolonged cerebral hypoxia, and the resulting brain injuries may include problems with attention, memory, and executive function.1PubMed Central. Neurocognitive impairments and brain abnormalities resulting from opioid-related overdoses: A systematic review A multicenter study found that among people with opioid dependence, those whose overdoses were severe enough to require resuscitation showed signs of impaired cognitive performance compared to those whose overdoses did not involve that level of oxygen loss.10PubMed Central. Effect of Overdose-Induced Hypoxia on Neurocognitive Performance in Individuals With Opioid Dependence: A Prospective Multicenter Study The practical effect is that some people wake up from a serious overdose with trouble thinking clearly, difficulty remembering things, or problems organizing their thoughts, and these issues do not always resolve quickly.
There are also injuries caused by being unconscious for hours in one position. When someone overdoses on opioids and collapses, the weight of their own body can compress muscles and nerves for long enough to cause what is known as compartment syndrome. One case report described a patient who, after being found unresponsive from a heroin overdose, developed severe pain and swelling in his left thigh from prolonged compression while unconscious.11PubMed Central. Opioid overdose with gluteal compartment syndrome and acute peripheral neuropathy Compartment syndrome can damage muscles and nerves permanently if not treated, and nerve injuries from the same mechanism can cause numbness, weakness, or pain that lingers for months. These complications are easy to overlook in the immediate focus on the overdose itself.
The Psychological Aftermath
Beyond the physical experience, overdose carries a psychological toll that is often underappreciated. Surviving an overdose is, for many people, a near-death event, and the brain processes it accordingly. A study of women in Baltimore found that experiencing an overdose was significantly associated with symptoms of post-traumatic stress, particularly intrusive thoughts and disturbances in mood and thinking. Women who had experienced an overdose had roughly twice the odds of endorsing intrusion symptoms and changes in mood or cognition compared to those who had not overdosed.12PubMed Central. Conceptualizing Overdose Trauma: The Relationships between Experiencing and Witnessing Overdoses with PTSD Symptoms among Street-Recruited Female Sex Workers in Baltimore, Maryland
The study also found that simply witnessing someone else’s overdose was associated with PTSD symptoms, though the link was weaker than for personal experience. This matters because people who use drugs often overdose in the presence of others who also use, meaning a single overdose event can traumatize multiple people at once.
The cruel paradox here is that PTSD symptoms from a prior overdose, including hyperarousal, emotional numbing, and avoidance, can actually increase the risk of future overdose. A person experiencing intrusive flashbacks or emotional disturbance may use more drugs to cope, raising the chance of another overdose. The stigma and poor treatment some survivors report receiving during the post-reversal period only deepens this cycle, making them less likely to call for help if it happens again.
Why People Around You May Notice Before You Do
One of the most important things to understand about overdose, especially opioid overdose, is that the person going through it often has no idea it is happening. The same drugs that slow breathing also suppress the brain’s alarm signals. You do not feel yourself suffocating. You do not feel your lips turning blue. The experience is closer to simply ceasing to be aware. This is why overdose deaths so often happen when someone is alone: there is no one to notice the warning signs that the person themselves cannot perceive.
For stimulant overdoses, the situation is different. The person is often painfully aware that something is wrong but may be too confused, paranoid, or physically impaired to seek help. Psychosis and paranoia can actually make someone resist assistance from others, believing that people trying to help them are threats. This creates a different kind of barrier to survival: not oblivion but terror and disorientation.
In either case, the people nearby, friends, family, or strangers, are often the ones who must recognize what is happening and act. For opioid overdose, the visible signs are a limp body, slow or stopped breathing, blue or grayish skin, and gurgling or snoring sounds. For stimulant overdose, look for extreme agitation, overheating, seizures, or someone clutching their chest. These external signs are often more reliable indicators of overdose severity than anything the person themselves can report.
How Mixed Substances Change the Picture
The rise of polysubstance use, taking multiple drugs at once or unknowingly consuming drugs laced with other compounds, has made the overdose experience harder to predict. Fentanyl contamination of cocaine, counterfeit pills containing unexpected opioids, and the combination of benzodiazepines with opioids all create overdose presentations that do not fit neatly into the categories described above.
Someone who takes cocaine laced with fentanyl might initially feel the racing heart and agitation of a stimulant overdose, only to have it abruptly replaced by the sedation and respiratory depression of an opioid overdose as the fentanyl takes hold. Mixing opioids with benzodiazepines is particularly dangerous because both suppress breathing through different mechanisms, and the combined effect can shut down respiration faster than either drug alone. People who mix alcohol with prescription sedatives face a similar compounding risk.
From the perspective of sensation, mixed overdoses are often chaotic. The body receives contradictory signals: stimulation and sedation at the same time, euphoria layered over panic, or numbness interrupted by sharp pain. Survivors of polysubstance overdoses sometimes describe the experience as feeling like their body was being pulled in different directions simultaneously, or simply as overwhelming confusion followed by blackout. The unpredictability is part of what makes these overdoses so dangerous, because neither the person nor the bystanders can easily tell what they are dealing with.