Jonathan Hayes – Notes On Forensic Medicine: Smell

Back by popular demand: Jonathan Hayes

Jonathan Hayes ( is a senior forensic pathologist in the New York City Medical Examiner’s Office, and author of PRECIOUS BLOOD (Harper 2007) and A HARD DEATH (Harper, 2009).

Notes on Forensic Medicine: Smell

by Jonathan Hayes MD.

My sense of smell is pretty acute, an extremely useful attribute in my food writing career but a double-edged sword in my career as a forensic pathologist. For example, it’s pretty easy for me to tell when a particular decedent has been drinking heavily, but I will admit that I had a pretty rough time with decomposition when I began in the business.

I should be more specific in my terms: decomposition is the natural breakdown of tissues after death. We divide decomposition into putrefaction (damp rot under the influence of bacteria), mummification (where the body shrinks as it dessicates in a dry environment) and adipocere formation (typically occurring in cool, damp places, like waterlogged coffins or bodies recovered from a lake, adipocere is a condition in which the body fat is chemically converted into a soapy material sometimes called “grave wax” – it’s an odd process, because the body decays, yet its form is preserved, almost “cast” in odd, cheesy-looking material.)

In the early stages after death, cellular metabolism slows as the internal systems begin to break down. Lack of oxygen in the tissues triggers an explosive growth of bacteria, which feed on the body’s proteins, carbohydrates and fats, producing gases that cause the body to smell and to swell. In 1885, the German physician Ludwig Brieger identified two nitrogenous compounds – putrescine and cadaverine – as the chemical basis of the smell of putrefaction; there are, in fact, a host of volatile compounds involved, including substances related to butyric acid. While together these chemicals may be characteristic of putrefaction, they’re encountered in other places, giving odor variously to bodily fluids, rancid butter, bad breath and stinky cheeses.

A body may release gases within hours after death, even without visible signs of decay. In cities, bodies are often found when a “neighbor complains of a foul odor”, a history so common it’s occasionally shortened to “NCFO”. More poetically, I’ve heard the smell of decomposition referred to as “the stench of loneliness”; those who have partners or family are usually discovered before their bodies rot.

It was in Boston that I encountered my first putrefied body. A resident in General Pathology at Boston University Medical Center, I spent a lot of time at forensic autopsies – the medical examiner’s office autopsy room was on the top floor of our building. My first winter there (thanks to indoor heating, bodies decompose all year round in temperate zones, too; the extreme dry heat means that we tend to see more mummification in winter than in summer), I wandered up to the autopsy room and opened the door to find them working on a very putrefied body.

A well-run mortuary doesn’t really smell; it is washed frequently and properly ventilated, and most bodies examined are fresh. But I’d never smelled anything like that putrefied body; it was an overwhelming odor, dense, wet, vile, almost shockingly sweet, like the vomit of a drunk; it seemed to coat the skin and settle into clothes. I felt nauseated, and stepped back outside the room, closed the door behind me and leaned against the wall, retching.

When I felt better, I went back into the autopsy room. The stench grew stronger as I approached the body and watched; a couple minutes later, I had to go back out and retch again. Then I went back in. I’m embarrassed to admit it took me a couple of years to get used to it. This makes me something of a lightweight: in NYC, each month we teach forensic pathology to large numbers of junior doctors, medical students, paramedics and EMT’s, and I’ve only rarely seen anyone have to leave the room.

The response to the odor, then, is very subjective; most people are surprised by their lack of an intense reaction the first time they see an autopsy. The context is important, of course – in an autopsy room, the surroundings are so clinical, and everyone is so matter-of-fact about the work that there isn’t much emotional space to abreact – the opening sequence of the TV show Quincy, where the cops are dropping like flies, is wholly fictitious.

My own intense response to the smell of putrefaction was fascinating to me. I’d never encountered it before; the closest I’d come was the smell of rotting grass in a compost pile back in my days on a country club grounds crew while I was in medical school. But humans are wired to find the smell repulsive for biological reasons – we know immediately when meat has gone bad, and we do not eat it. (An interesting contrast: I learned on a wildlife documentary that hyenas thrive on rotten carrion. Apparently, the digestive tract of the hyena is so robust that it can happily consume anthrax-infected flesh without problem – a superb evolutionary advantage, because that limits competition for their food. Indeed, the hyenas in the film weren’t just wolfing down the rotting flesh, they were rubbing themselves on it, rolling in it like cats with catnip.)

Occasionally I’ve heard medical examiners joke that the smell of decomposition is “the smell of job security”. With time, it’s got that I don’t mind the smell any more – I may still wince a little when I first encounter the body, particularly when it’s an exhumation, where the body has been sealed tight with its gases for years, decades even. But after the first couple of minutes, I barely notice the smell – the overwhelmed nose shuts down quickly. So, yes, I’m better about it now. But still a very long way from the hyena’s embrace of decay…

*    *    *

The huge Indonesian corpse flower (titan arum) blooms once every six years, and attracts insects by releasing chemicals including putrescine and cadaverine. It’s a pretty spectacular trick: not only does the broad petal that wraps the pollen-bearing spadix have the ruddy maroon color of rotting flesh, the plant generates temperatures equivalent to the temperature of the human body, volatilizing its scent to attract even more insects.


18 replies
  1. Lee Lofland
    Lee Lofland says:

    CJC – I sent your question to DP Lyle, M.D.

    Dr. Lyle is the author of Forensics, A Guide For Writers and Forensics for Dummies. Here’s his reply:

    Under those conditions a faint musty odor would appear in about 24 hours and by 48 the odor of decomposition would be easy to detect. It would then increase from there and by about 96 hours would be very strong. SO if an odor of decay was detected, the body could be 24 hours old or more.

    Dr. Lyle also writes the blog The Writers Forensics Blog

  2. CJC
    CJC says:

    With the temperature staying around 75 deg F how soon would a body begin to smell after death? I hope to alleave the concerns of a friend on how long her mother may have lain dead without discovery. There was no smell of decaying. Could it have been as long as 5 days or would two days be enough for the smell of decomposition to be evident? This is a tough one to search on the internet.

  3. Jonathan Hayes
    Jonathan Hayes says:

    Yes, it is a disadvantage not being able to smell properly. Of course, not everyone can smell cyanide – like being able to roll your tongue, that’s an ability that is genetically determined.

    And don’t worry about the smell issue – you’ll be fine. You’ll find that when you’re on the spot, you can do just about anything. Sometimes medical students or pre-med students are disturbed by what they see in their first autopsy; I think this is largely anxiety, the result of them building it up so that their reactions to the autopsy are some kind of test as to whether or not they’ll be a good doctor.

    A good doctor is someone who cares about their patients, listens to them properly, has the skill to diagnose them correctly and the intelligence to treat them appropriately. A strong emotional reaction to their first time seeing a human body disassembled is a mark of sensitivity that will probably stand them in good stead in a medical career.

    When med students DO get upset, I point out to them that the first time Christiaan Barnard entered an anatomy lab, he was so distressed that he immediately rushed out and was sick; he later went on to conduct the first human heart transplant.

  4. MysteryWriter
    MysteryWriter says:


    As someone with a very strong sense of smell, I wear the Wuss badge. I can read about things associated with death, including a fascinating study on body farms and it doesn’t bother me, but the odor of anything decaying? : – p

    I think Forensics is extremely interesting, and I love to write about it, but I could never do it.

    Hubby had a job years ago where he often had to go to the morgue and he said you never forget the smell of death or forget seeing children there.

    I can write about it (thanks to wonderful folks like you and Lee who share your expertise) but I could never witness an autopsy. I’ll gladly take your word for it.

    Thanks for sharing.

  5. jennam
    jennam says:

    I’ve read that Vicks is also bad because it blocks out useful smells (cyanide, for example.)

    Thanks for this post. I’m pre-med, and I have seriously strong gagging reflexes to certain smells. I’ve been worried that that might be a major handicap in the future, so it’s good to hear it can be overcome. 🙂

  6. Jonathan Hayes
    Jonathan Hayes says:

    Haha, Terry! The funny thing is that some detectives are amongst the most perfumed beings I know, so when they come in for a homicide… Of course, I can’t deny them access to my autopsy room, but, well, you know.

    Mary-Frances, I take it that you are, then, nasty, since you went with “Dr. Hayes”…

    Pau(l) – I’ve not smelled that many decomposing animals, but since we are all made of pretty similar flesh, and carry (I imagine) fairly similar organisms on us, I can imagine that a decomposing animal could smell similar to a human in a similar state. I’ve certainly seen cases where bodies are found in a state of advanced decomposition because the neighbors had just assumed that some animal had died in the wall.

    SZ: you’re right, it’s quite healthy to be sensitive to this type of situation. However, in any male-dominated working environment, there tend to be rather coarse social infrastructures which use criteria like Wussiness for assigning rank and respect. In these sorts of environments, it’s best not to be seen as a Wuss. Not that there’s anything wrong with that…!

  7. Terry
    Terry says:

    I’ve not had to deal with a dead human body, but hubby’s work in marine mammal carcass salvage has provided its share of unpleasant (being polite there) odors. There’s something about blubber decomposing in the sun that’s … yucky. And the fats permeate the bones, so no matter how many times hubby tells me they’ve been cleaned and don’t smell — well, he’s surrounded by it, but I walk into his office and can smell it every time. And I’d know immediately if he came home after a necropsy and had nicked a glove. One drop. And I don’t have a particularly sensitive sense of smell. That stuff is gross.

    The ONLY time I’ve denied him access to our bed was the night he got home after some stranding and the resultant necropsies, and was too tired to shower so he doused himself with aftershave. Those are two smells that just don’t mix!

  8. Falcocop
    Falcocop says:

    Hello Jonathan,

    Interesting blog. I am lucky, I do not have any great problem with the smell of decomposing bodies. Personally I have never seen anyone faint in the P.M. Room but I certainly have seen them leave. It is not something everyone can watch and I would never critisise them for it.

    There is also a saying that you cannot mistake the smell of a decomposing corpse. That is only half true because you need to know what the smell is like first of all and with some members of the public you need to be able to recognise what a dead body looks like. We had quite an incredible situation this week but out of respect I had best not put this on the Internet as I am not sure just how safe this site is. If you wish I could email you later.


    Coroners Officer, England

    “I see dead people”

  9. Lee Lofland
    Lee Lofland says:

    I’ve never experienced any real difficulty with the smells associated with autopsies. The only ones that slightly made my stomach twist a bit were badly burned bodies.

    I’m with Jonathan, it’s the torch for me, too, when I’m gone. I have attending autopsies to thank for that decision. And, I think I’ll pass on the slicing and dicing, if possible.

  10. Jonathan Hayes
    Jonathan Hayes says:

    Also! I’m writing this in my spare time (in bed in Paris, actually): if you call me Dr. Hayes, I’ll think you’re trying to sell me malpractice insurance. It’s Jonathan – Dr. Hayes if you’re nasty…

  11. Jonathan Hayes
    Jonathan Hayes says:

    Elena, I’ve not seen many people react strongly to an autopsy, at least overtly – I’m sure people have some fairly intense internal discussions before, during and after.

    Largely I think there’s a kind of momentum of protocol – people know how they’re supposed to act, and act that way. I think some people psych themselves up for what they’re about to see, and can get stressed that way. And when one visitor gets upset, then others may follow suit.

    But mostly, it’s matter of fact, this is what it is/this is what it looks like. It’s serious stuff, and that doesn’t leave a lot of room for abreaction.

  12. Jonathan Hayes
    Jonathan Hayes says:

    Lee – thanks for the zippy fix on the thing! Sorry if I’d dropped out that paragraph when I sent it to you originally.

    jnantz – Sometimes people smear Vicks Vapor Rub under their noses, or inside their masks. This should NEVER be done, since it immediately marks them as absolute wusses, ripe for mocking in the autopsy room (should mocking be deemed necessary) (which it should). The camphor smell of Vicks is supposed to conceal the smell of decomposition; instead of having an unpleasant odor that gradually fades, you sear your nostrils with Vicks. Plus everyone knows you’re a wuss – with a capital W, actually: everyone knows you’re a Wuss.

    I, of course, WAS a Wuss, but I was still man enough to overcome my innate revulsion and get on with the important work that needed to be done. I still don’t understand why my reaction was so strong, whether it was something I’d encountered in childhood and blotted out, or whether we’re just hard-wired for revulsion and particular odors – probably the two of them.

    Since I’ve not noticed any of my colleagues past or present ever having any difficulty with this, I think it’s largely a learned behavior. We all note it as an unpleasant smell, but it’s not an impediment to an autopsy (at least with experienced forensic pathologists).

    I suspect that a good part of my revulsion at the beginning related not so much to the smell itself as to the sight of a body so brutally corrupted. It was hard to see what we become, I think, and part of my reaction was dismay at our fate. Which is why, when I die, after I’ve given up whatever organs might be useful, I shall be converted promptly and neatly into ash, and sprinkled around the dog run at Union Square Park in New York. (Just kidding.) (About the dog run, I mean – it’s definitely cremation for yrs truly.)

    Anyway, long and discursive answer to your question, jnantz! Long story short: Vicks Vapor Rub/disguises the smell/might have helped me some but in the long run it’s something you accept.

    Final Fun Fact! The place I’ve seen most Vicks used was when I was writing about the rave scene, back when I first started writing: when people take Ecstasy (MDMA, the drug of choice of the rave scene), their senses become profoundly heightened, so people on MDMA tend to do things that are sensually stimulating. Apparently, inhaling Vicks while you are under the influence is a mind-blowingly great experience; many ravers carry Vicks sticks. Since early raves often took place in dusty warehouses, sometimes the kids would wear paper masks to filter the dust; in one of those “peanut butter on my chocolate/chocolate in my peanut butter” moments of blinding inspiration, they also began to smear the Vicks on the inside of their masks, then run around all night breathing through the Vicks, to tremendous effect.

  13. Elena
    Elena says:

    It’s delightful to know that I’m reasonably normal, at least as far as autopsies are concerned. I’ve watched two of them, one of which was pretty stinky, but they were so fascinating that I didn’t have a negative reaction.

    I used my experience in a work of fiction only to have my agent argue with me that everyone would have a strong negative reaction to their first autopsy. Wish I had “known” you then.

  14. jnantz
    jnantz says:

    Dr. Hayes, unfortunately I’ve seen SILENCE OF THE LAMBS, but never read it. I remember them placing something white, some kind of compound, under their noses while working on the body that was pulled from the river. What was that, if it’s real and not fictitious, and would it have helped you? If it is real, does it make one come across as more of a lighteight to use it?

  15. Lee Lofland
    Lee Lofland says:

    Dr. Hayes is experiencing very limited email service right now, so his responses to your questions may be delayed.

    I’ve also been experiencing Hotmail troubles for the past few days. In fact, I don’t have service at all right now. If you’ve emailed me and I didn’t respond you can try Maybe I’ll remember to check that account…

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