Corpse Sickness in Project Zomboid (Build 42): How It Works and How to Stop It
TL;DR: corpse sickness starts only when more than 5 corpses are counted around you, and it gets worse with every extra body up to 25. It fills the same Sick meter as food poisoning (Queasy, Nauseous, Sick, Fever), and only the last stage, Fever, drains health. To cure it, leave the area: the meter falls on its own once nothing is feeding it, as long as you do not also have food poisoning. Lemongrass knocks it down faster. A gas mask, half mask respirator or NBC mask with a filter in it blocks it completely, so does an SCBA or hazmat suit that is switched on with air in the tank. Then get rid of the bodies: burn them with petrol and a lighter, or bury five per grave.
Corpse sickness is the most common "my character died and I do not know why" story in Build 42. You clear a store, fight at the door for an evening, sleep in the back room, and wake up with a fever. Everything on this page is read from the Build 42.21 game code and scripts that our Project Zomboid servers run, not from older wiki pages, so the numbers below are the ones the game actually uses.
What corpse sickness actually is
There is no separate "corpse sickness" bar. Rotting bodies add to the same sickness value that bad food raises, and the game shows it with the same moodle and the same four stages:
| Stage | Moodle text | What it means for you |
|---|---|---|
| 1 | Queasy: "Not feeling too good." | A warning. No health loss from sickness yet. |
| 2 | Nauseous: "Weak with illness." | Still no health loss from sickness. Leave now. |
| 3 | Sick: "Very weak and unwell." | Last stage before damage. Get out and stay out. |
| 4 | Fever: "Increasing danger of becoming rat food." | Health drains. This is the stage that kills. |
In the health code, sickness only takes health away when the moodle is at stage 4 and the sickness value is higher than the zombie infection value. That is why players say "once you get a fever it's basically over": the first three stages are free warnings, the fourth one is where you start dying, and it does not stop while the bodies are still around you.
It also explains why corpse sickness gets mistaken for the Knox infection. The Sick moodle is driven by whichever is highest of zombie fever, zombie infection and this sickness value, so the Knox infection and corpse sickness show exactly the same moodle, and a character with no bite at all can look infected. If you have no bite, laceration or scratch from a zombie and you spent time near bodies, it is almost certainly corpse sickness.
How the game counts corpses
The counting is more specific than "bodies within 20 tiles", which is what most guides repeat. The map is split into 8 by 8 tile chunks, and the game adds up the corpses in the chunk you stand in plus the eight chunks around it, on your floor only. That is a 24 by 24 tile block, so a body can count from anywhere between about 8 and 15 tiles away depending on where in your chunk you are standing.
| Where you are | What counts | What does not count |
|---|---|---|
| Outdoors | Outdoor corpses on your level in the 24 by 24 block | Corpses inside any building |
| Inside a building | Corpses inside that same building, on your floor | Corpses outside, in other buildings, or on other floors |
| Zombie Health Impact on (sandbox) | Living zombies in a 25 by 25 tile block around your chunk count as well, with the same indoor and outdoor split | Off by default |
Two practical consequences follow from that split. First, a pile of bodies on the lawn does not count while you are inside the house, and a body in the kitchen does not count while you are out on the lawn. Dragging the corpses out of the building you are looting is enough to stop them counting against you indoors. Second, going upstairs works too, because only your own floor is counted.
Nothing happens at all with 5 or fewer corpses. The 6th body is the first one that matters, and the count is capped at 25, so a pile of 25 is the worst case and a pile of 200 is no worse.
How fast it builds: the real numbers
For every corpse above five, the game adds a fixed amount of sickness per tick. The amount depends on the Decaying Corpse Health Impact sandbox setting. When nothing feeds the meter any more, it drains back down at a fixed recovery speed. Both use the same game clock, so the ratio between them tells you exactly how long you need to stay away to undo an hour of exposure.
| Setting | Build-up per extra corpse, compared with the recovery speed | At 25 or more corpses | Fresh air needed to undo 1 in-game hour beside 25+ corpses |
|---|---|---|---|
| None | 0 (off) | 0 | None |
| Low | 1% | 20% | about 12 minutes |
| Normal (default) | 7% | 140% | about 84 minutes |
| High | 11% | 220% | about 2 hours 12 minutes |
| Insane | 100% | 2000% | about 20 hours |
A worked example on Normal: standing near 10 corpses means 5 bodies above the threshold, so the meter fills at 35% of the speed it recovers. An hour there costs you about 21 minutes away. Remember that none of that recovery happens while you stay: with six or more bodies counted, the meter only rises. That is why a long fight at one doorway, or a night's sleep beside the pile, is how characters reach Fever. Insane is a different game: 25 bodies fill the meter twenty times faster than it drains.
The one condition on recovery: the meter only drains while nothing is feeding it and you have no food poisoning. If you ate something bad as well, the corpse part will not clear until the poisoning has.
Traits that change it
- Resilient: corpse sickness builds at 75% of the normal speed.
- Prone to Illness: it builds at 125%.
Neither trait changes the recovery speed, only the build-up.
Lemongrass helps here too
Because corpse sickness and food poisoning share one meter, the items that lower food sickness lower corpse sickness too. In the 42.21 item scripts Lemongrass carries a food sickness change of minus 12 and Ginger Root minus 1. The game skips the effect while a previous herb's effect timer is still running, so eat them one at a time rather than in a stack. Treat them as a boost to recovery, not a substitute for leaving.
Masks and gear that block it
The game checks everything you are wearing and uses the single best piece. Protection does not add up across items.
| Worn item | Protection | Condition |
|---|---|---|
| SCBA, or Hazmat Suit | 100% | Switched on, with a tank that still holds air |
| Gas Mask, Half Mask Respirator, Nuclear Biochemical Mask | 100% | A filter fitted that still has charge left |
| Improvised Gas Mask | 85% | A filter fitted that still has charge left |
| Bandana, Rag Bandana (Face), Dust Mask, Surgical Mask, Shemagh (Fully Closed or Face Covering), Burlap and Cloth Headwraps, plus a Gas Mask, Half Mask Respirator or Improvised Gas Mask with no usable filter | 25% | Just worn on the face |
| Nuclear Biochemical Mask with no filter | 0% | It has no protection value of its own |
Three details explain most of the "I died wearing a mask" posts:
- Filters drain while they protect you. Every tick a filtered mask blocks corpse sickness, the filter loses charge in proportion to how many bodies are around. Once it is empty, a gas mask or respirator drops to the 25% of a plain face covering. Sleeping beside a big pile is exactly how a filter runs dry without you noticing.
- The hazmat suit has to be switched on. The Hazmat Suit counts as an SCBA, but only while it is activated and its tank has air. Worn switched off, or with an empty tank, it does nothing against corpse sickness.
- A bandana is not a gas mask. 25% only slows the build-up. Near 25 bodies on Normal, a dust mask still fills the meter at 105% of the speed it drains once you leave.
How to get rid of corpses
The game's own survival guide says it plainly: too many corpses in one area causes sickness, and they can be buried in graves or burned with gasoline and a fire source. Here is what each method needs in 42.21.
| Method | What you need | Details from the game files |
|---|---|---|
| Drag | Nothing | Hold the Interact key (E by default) beside a corpse to grab it, and again to drop it. The context menu also offers Throw Corpse Over Fence and Throw Corpse Through Window. |
| Burn | A lighter, matches or another fire starter, plus a container of petrol | The game equips the fire starter in your main hand and the petrol in the other. Each corpse uses 0.1 L of petrol and one use of the lighter, so a full 10 L gas can covers 100 bodies. It starts a real fire on that tile, so do it away from walls, fences and trees. |
| Bury | A Spade, Shovel, Wooden Spade or Entrenching Tool | Dig Graves on natural ground (grass or dirt). Each grave holds 5 corpses, then use Fill Grave. Burying takes almost three times as long as burning a body, and only works at ground level. |
| Campfire | An unlit campfire | Place corpse on campfire, then light it. The game refuses while the campfire is already burning. |
For a base, the fastest routine is to drag bodies to one outdoor spot well away from your buildings, burn them in a batch, and keep a can of petrol for it. If you live inside a map building, keep the indoor count at five or fewer and the pile outside will not count against you while you are indoors.
For blood, mops and bleach after the cleanup, see our cleanup and hygiene guide. If you are not sure the sickness is from corpses at all, the sickness guide covers food poisoning, colds and the Knox infection, and cure queasy walks through the causes of the first stage.
Server settings for admins
Three sandbox settings in servertest_SandboxVars.lua (or the file for your server's name) control all of this:
| Key | What it does | Values |
|---|---|---|
DecayingCorpseHealthImpact | The build-up speed in the table above | 1 None, 2 Low, 3 Normal, 4 High, 5 Insane |
ZombieHealthImpact | Whether nearby living zombies count like corpses | true or false |
HoursForCorpseRemoval | In-game hours before dead zombie bodies disappear from the world. At 0, maggots do not spawn on corpses. | Hours |
What the built-in presets ship with in 42.21:
| Preset | Decaying Corpse Health Impact | Zombie Health Impact | Hours for corpse removal |
|---|---|---|---|
| Apocalypse, Outbreak, Rising | Normal (3) | false | 216 (9 days) |
| Extinction | High (4) | true | 216 (9 days) |
On a busy multiplayer server corpses pile up fast at popular loot spots, which is where most of these deaths happen. Lowering HoursForCorpseRemoval clears bodies sooner and also reduces the number of corpse objects the server has to track. Change sandbox values with the server stopped, then start it again. Our sandbox settings guide shows where the file lives.
Frequently asked questions
How do you cure corpse sickness in Project Zomboid?
Move away from the bodies. The sickness meter drains on its own once fewer than six corpses are counted around you and you have no food poisoning. Lemongrass lowers the same meter. Then burn or bury the corpses so you do not walk back into it.
How many corpses cause corpse sickness?
More than five. With five or fewer corpses counted around you nothing happens. From the sixth body the build-up grows with every extra corpse, up to a cap at 25.
What is the corpse sickness radius?
The game counts corpses in the 8 by 8 tile chunk you stand in and the eight chunks around it, on your floor only: a 24 by 24 tile block. Indoors it only counts bodies inside the same building; outdoors it only counts bodies outside.
Does a mask stop corpse sickness?
A gas mask, half mask respirator or NBC mask with a working filter blocks it completely, as does an SCBA or hazmat suit that is switched on with air. An improvised gas mask with a filter blocks 85%. Bandanas, dust masks, surgical masks and shemaghs only block 25%.
Can corpse sickness kill you?
Yes. It only damages health at the fourth stage, Fever, but it keeps rising while you stay near the bodies, so sleeping or fighting beside a large pile can take a character from Queasy to dead.
Can you turn off corpse sickness?
Yes. Set Decaying Corpse Health Impact to None in the sandbox options, or DecayingCorpseHealthImpact = 1 in the server's sandbox file.
Running a long multiplayer world where the loot spots fill with bodies? Host a Project Zomboid server with Supercraft, tune the corpse settings for your group, and keep the run going.