A human body left at moderate outdoor temperatures for one week is typically in the late bloat stage of decomposition, swollen with internal gases, discolored in shades of green and dark red, and beginning to emit a powerful odor. The specific appearance varies enormously depending on temperature, humidity, and whether the body is indoors, outdoors, or submerged in water, but the broad pattern is consistent enough that forensic scientists use recognizable stages to describe it. What follows is a frank, evidence-based account of the changes a body goes through in that first week and the factors that shift the timeline.
The Bloat Stage and Why the Body Swells
Within the first day or two after death, the body’s own enzymes begin breaking down cells from the inside out, a process called autolysis. Bacteria that lived harmlessly in the gut while a person was alive start migrating into surrounding tissues, no longer held in check by the immune system. These bacteria feed on the body’s soft tissues and produce gases, chiefly methane, carbon dioxide, and hydrogen sulfide, as metabolic byproducts.1PubMed Central. The Thanatomicrobiome: A Missing Piece of the Microbial Puzzle of Death Those gases have nowhere to go, so they accumulate in the abdomen, chest, and limbs, inflating the body like a balloon.
By one week at warm ambient temperatures, the abdomen is visibly distended and the face and extremities are puffy. Research on decomposition timelines shows the bloated stage typically spans roughly day two through day ten, depending on conditions.2Forensic Science International. Factors affecting decomposition and Diptera colonization So at the seven-day mark, a body in a warm outdoor setting is often near the peak of bloating or just beginning to transition into the next stage, called active decay. The swelling can be dramatic enough to make a person unrecognizable to family members, with the tongue protruding, the eyes bulging, and the features distorted beyond what most people expect.
Color Changes and Marbling
Skin color changes are among the most striking visual differences. Within the first couple of days, a greenish discoloration usually appears on the lower right abdomen, right over the cecum where gut bacteria are most concentrated. Over the next several days, that green spreads outward across the abdomen, chest, and limbs. By one week, the trunk and much of the body may show a patchy mix of green, dark red, and purplish-black tones.
One hallmark of this stage is marbling, a branching, vein-like pattern visible through the skin. As bacteria spread through the vascular system, they break down hemoglobin in the blood, producing sulfhemoglobin and other pigments that trace the path of blood vessels just beneath the surface. The result looks like a dark map of veins drawn under the skin. Marbling typically becomes prominent during the bloated stage and is commonly observed at the one-week point in warm conditions.2Forensic Science International. Factors affecting decomposition and Diptera colonization
The skin itself becomes fragile. A phenomenon called skin slippage occurs as the outer layer of skin loosens from the tissue beneath it, sometimes peeling off in sheets when touched. Blisters filled with fluid may form on the surface. Hair can pull away from the scalp with minimal resistance. These changes are all consequences of the same bacterial and enzymatic breakdown happening below the surface.
Purge Fluids
As gas pressure builds inside the body, it pushes decomposition fluids upward and outward through the path of least resistance. The most common visible result is a dark, foul-smelling liquid that seeps from the nose and mouth, sometimes called purge fluid. This fluid is a mixture of blood breakdown products, liquefied tissue, and bacterial byproducts. Forensic researchers note that this purging of putrefactive fluids from the nose and mouth is one of the most commonly encountered decomposition phenomena, and it has occasionally been confused with bleeding from injuries sustained before death.3PubMed Central. Artefacts due to putrefactive gas production – an overview
Gas pressure can also force fluids from other body openings. The overall effect contributes to the staining and soiling of whatever surface the body rests on, and by seven days there is typically a visible pool or stain beneath the torso, head, and sometimes the limbs.
The Smell of Decomposition
Odor is one of the defining features of a week-old body, and it is far more intense than most people imagine. The smell is not a single chemical but a complex cocktail of hundreds of volatile compounds released as tissues break down. During the bloated stage, analysis of the gases being emitted shows that alcohols make up more than a third of volatile emissions, while carboxylic acids account for another roughly 35 percent; nitrogen-containing compounds also become significant, rising above 10 percent of total emissions.4PLOS ONE. Enhanced Characterization of the Smell of Death by Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectroscopy (GCxGC-TOFMS)
In practical terms, the odor is sweet, sickly, and penetrating, and it permeates clothing, upholstery, and porous building materials. People who have encountered it frequently describe it as unlike any other smell. It carries downwind and can be detected from a considerable distance outdoors. The hydrogen sulfide component gives it a rotten-egg quality, while other compounds add notes that are harder to describe but universally recognized as deeply unpleasant. At one week in warm conditions, the smell is typically strong enough to alert anyone in the vicinity that something is seriously wrong.
Insect Activity at One Week
In an outdoor setting, flies are often the first organisms to arrive after death, sometimes within minutes. Blowflies and flesh flies lay eggs in moist openings like the eyes, nostrils, mouth, and any wounds. Within a day or two, those eggs hatch into larvae, and by the end of the first week, substantial maggot masses are present, particularly around the head and any exposed soft tissue. Research confirms that internal temperature of the body actually rises as maggot colonies grow, generating their own metabolic heat during feeding.2Forensic Science International. Factors affecting decomposition and Diptera colonization
The larvae are not just passive residents. They actively accelerate decomposition by consuming soft tissue and creating breaks in the skin through their feeding. Beetles and other scavenging insects may also arrive during the first week, though their role tends to increase later. In outdoor environments with full insect access, a body at seven days may already show noticeable tissue loss around the face, particularly the eyes and lips.
How the Setting Changes Everything
The description above assumes a body lying outdoors in warm weather, which is where decomposition proceeds most quickly. Change the setting and the one-week picture changes drastically.
Indoor Versus Outdoor
Bodies found indoors decompose more slowly for a simple reason: insect access is restricted. A study comparing indoor and outdoor decomposition found a delay of about five days before indoor remains were first colonized by insects, while outdoor remains attracted flies almost immediately.5PubMed. Comparison of decomposition rates and faunal colonization of carrion in indoor and outdoor environments Fewer insects means less tissue destruction and slower progression overall. Enclosed spaces like tents or sealed rooms still get colonized eventually because flies can lay eggs on gaps and seams, but the infestation is reduced and delayed compared to full outdoor exposure.6PubMed. Decomposition and insect succession of pig cadavers in tents versus outdoors – A preliminary study
An indoor body at one week in a heated apartment may look similar to what is described above, with bloating, discoloration, and odor all present but with less insect damage. An indoor body in an air-conditioned space or a cool basement may still be in the early-to-mid bloat stage with less dramatic swelling. The bacterial processes still proceed, just more slowly when temperatures are low.
Cold Environments
Temperature is probably the single most important variable. In cold weather, decomposition slows dramatically. Research on remains in extreme cold found that temperature and snow depth were the most important predictors of how quickly a body breaks down.7PubMed Central. Decomposition in an extreme cold environment and associated microbiome—prediction model implications for the postmortem interval estimation A body outdoors in winter may show relatively little visible change at one week beyond livor mortis, the purplish pooling of blood in the lowest parts of the body, and the early beginnings of greenish discoloration. Even bodies kept in mortuary refrigerators at around 4°C still produce some internal gas over a three-day period, suggesting that bacterial activity does not stop entirely in the cold, just slows to a crawl.8PubMed. Progressive gas formation in a deceased person during mortuary storage demonstrated on computed tomography
Water Submersion
Bodies recovered from water present a different set of changes. Cooler water temperatures and the anaerobic environment slow the typical decomposition sequence, so a submerged body at one week often looks less decomposed than a body left in open air at the same temperature.9PubMed Central. Decomposition Changes in Bodies Recovered from Water However, prolonged water exposure introduces its own distinctive changes. The skin of the hands and feet wrinkles and whitens, sometimes called washerwoman skin, and the outer layer of skin loosens more uniformly than in air exposure. Gas production still occurs, and submerged bodies eventually float to the surface once enough gas accumulates.
Water also favors the formation of adipocere, a waxy, soap-like substance that forms when body fat reacts with water and bacteria. Early-stage adipocere has been confirmed on tissue submerged in lake water within the first weeks of submersion, and the process requires an abundance of certain bacteria to break down fat into free fatty acids.10PubMed. Bacterial populations associated with early-stage adipocere formation in lacustrine waters At just one week, adipocere formation is rarely advanced enough to be a dominant feature, but the early chemical changes in body fat may already be underway in warm, stagnant water.
What Happens to the Surrounding Ground
A body does not decompose in isolation. The fluids that leak from the body seep into the soil or surface beneath it, creating what researchers call a cadaver decomposition island. This patch of ground receives a concentrated dose of nutrients, particularly carbon and nitrogen. In one study, the nitrogen content in soil directly beneath a decomposing body more than doubled within the first 15 days, rising from about 0.4 percent to over 1 percent. Measurable chemical enrichment of the soil was detected as early as day 10, during the active decay stage.11PubMed Central. Human cadaver decomposition islands and forensic taphonomy: gravesoil δ 13 C and δ 15 N enrichment patterns in short (30 d) and extended (900 d) postmortem intervals
At the one-week mark, this means the ground beneath and immediately surrounding the body is already chemically distinct from the surrounding soil. The vegetation in that area eventually responds to the nutrient surge. Forensic scientists have used this soil chemistry signature as a tool in investigations, and it can persist for years after the body is removed. For anyone who encounters a scene where a body has been lying outdoors for a week, the staining and saturation of the ground surface is often one of the most noticeable visual features alongside the body itself.
How Forensic Scientists Read These Changes
Estimating how long someone has been dead, known as the postmortem interval, is one of the central tasks of forensic investigation. At the one-week mark, forensic pathologists rely on a combination of visual indicators: the degree of bloating, the extent of discoloration and marbling, whether skin slippage has begun, the presence or absence of purge fluids, and the size and development of insect larvae. Each of these provides a rough bracket for the time since death, but none is precise on its own because environmental conditions create so much variability.
Newer approaches are supplementing the traditional visual assessment. Researchers have used postmortem CT scans to track gas accumulation inside organs over the first week, measuring how the volume of gas in the body increases day by day.12Indian Journal of Forensic and Community Medicine. Correlation of CT measurements of total body gas volume and hounsfield units with post-mortem interval Others have investigated whether the microbial communities that colonize the skin after death change in a predictable enough pattern to serve as a biological clock, using machine learning models to estimate the postmortem interval from skin microbiome samples.13PLOS ONE. A Machine Learning Approach for Using the Postmortem Skin Microbiome to Estimate the Postmortem Interval These methods are still being refined and are not yet standard practice, but they show how much information the decomposing body carries about its own timeline.
The visual staging system used in forensic science, which divides decomposition into fresh, bloat, active decay, advanced decay, and skeletonization, is useful but imperfect. Bodies do not transition neatly from one stage to the next on a fixed schedule. Different parts of the same body can be in different stages simultaneously, especially when one side is exposed to sun and the other is pressed against the ground. The one-week snapshot is really a range of possible appearances rather than a single fixed image.
The Psychological Reality of Encountering a Decomposing Body
For people who come across a week-old body unexpectedly, or for the first responders and forensic professionals who handle such cases routinely, the experience carries a real psychological weight that is worth acknowledging. Research based on a decade of forensic and criminal investigations in Tanzania found that bodies in advanced decomposition, along with those that were bloated or mutilated, were the most psychologically challenging specimens for forensic practitioners to work with.14African Research Reports. Handling dead bodies in forensic investigations and its temporal psychological effects
Common reactions reported by professionals include loss of appetite, temporary cessation of meat consumption, intrusive thoughts, vivid mental images that replay after leaving the scene, and generalized anxiety. These are not signs of weakness but normal responses to an inherently disturbing stimulus. The research emphasizes that timely psychological support makes a meaningful difference in mitigating these effects. For non-professionals who stumble on a decomposing body, whether a deceased neighbor found during a welfare check or a discovery made while hiking, those same reactions can occur and the same principle applies: talking to a mental health professional afterward is not an overreaction.
Why Individual Bodies Can Look So Different at the Same Time Point
If you have read this far, you might have noticed a tension in the descriptions: the article gives a general timeline, but every section includes caveats about conditions. That tension is real and reflects one of the most consistent findings across decomposition research. Two bodies that died at the same moment can look wildly different one week later depending on a handful of variables.
Body composition matters. A person with more body fat tends to decompose differently than a lean individual because fat tissue holds heat and provides a rich substrate for bacterial activity. Clothing and wrapping can insulate the body, trapping heat and moisture, which speeds some processes while potentially limiting insect access. Cause of death can also play a role: a body with open wounds gives insects and bacteria more points of entry, accelerating breakdown, while a body with certain medications or toxins in the system may decompose at an altered rate because those chemicals affect bacterial growth.
Altitude, soil type, sun exposure, rainfall, and whether the body is on a paved surface versus bare earth all contribute. A body lying face-down on concrete in a parking garage during a mild autumn week will look meaningfully different from a body lying in tall grass in the summer heat, even if both have been dead for exactly seven days. Forensic scientists account for this variability by using accumulated degree-days, a measure that combines temperature and time, rather than calendar days alone, when estimating how far decomposition has progressed. A week in July in Arizona packs far more thermal energy than a week in January in Minnesota, and the decomposition reflects that difference starkly.
All of this is why descriptions of “what a body looks like at one week” are best understood as a central tendency, not a guarantee. The bloating, discoloration, marbling, odor, and early tissue breakdown described in this article represent the general trajectory, but the actual appearance at any given scene can range from surprisingly intact to nearly unrecognizable, all within the same seven-day window.