Food Poisoning Symptom Checker
Pick how long ago you ate the suspect food, check the symptoms you have, and flag any risk factors. The tool maps that pattern to the pathogens that most often cause it and to an action tier: home care, call your doctor or 811, urgent care, or 911. Onset timing alone is a strong clue, because preformed toxins strike within hours while Listeria can take weeks.
Educational only, not a diagnosis, and built for adults. For symptoms in children under 18, consult a pediatrician directly. Pair this with the how long leftovers actually last guide and keep the Family Fridge and Freezer Temperature Log on the fridge.
Screen your symptoms
Choose when you ate the suspect food, check the symptoms you have now, and flag any risk factors. Results update instantly with the likely cause, an action tier, and the next steps for that exact pattern.
Norovirus (probable)
Most likely cause from your pattern. This is not a diagnosis. See a healthcare provider to confirm.
Suggested next steps: home care
Important warnings
How to use this tool, and what it can and cannot do
Pick the window since you ate the suspect food, check the symptoms you have, and flag any risk factors. The tool returns the pathogens that most often produce that pattern, an action tier, the next steps for that tier, and the warnings that matter most. It can help you decide how urgently to seek care and which mistakes to avoid. It cannot diagnose you: only a clinician can do that, often with a stool culture. This tool is for adults. For symptoms in children under 18, consult a pediatrician directly. When in doubt, treat it as serious and call your provider, 811, or 911.
Pathogen quick-reference
The eight pathogens behind most foodborne illness, grouped by how fast they hit. Incubation periods follow CDC and the Public Health Agency of Canada (PHAC).
| Pathogen | Typical onset | Hallmark | Common source | Course |
|---|---|---|---|---|
| Staphylococcus aureus toxin | 30 min to 8 hr | Sudden violent vomiting, no fever | Food held warm at a potluck or picnic | Self-limiting 24 to 48 hr |
| Bacillus cereus toxin (emetic) | 30 min to 8 hr | Rapid vomiting | Rice, pasta, starchy food left out | Self-limiting |
| Norovirus | 12 to 48 hr | Watery diarrhea, vomiting, low-grade fever | Person to person, shellfish, fresh produce | Self-limiting 1 to 3 days, highly contagious |
| Salmonella | 6 hr to 6 days | Fever, cramps, diarrhea (sometimes bloody) | Poultry, eggs, produce | Self-limits 4 to 7 days |
| Campylobacter | 2 to 5 days | Fever, abdominal pain, diarrhea (often bloody) | Poultry, raw milk | Most common bacterial cause in Canada |
| E. coli O157:H7 | 1 to 10 days (often 3 to 4) | Bloody diarrhea, severe cramps, little or no fever | Ground beef, leafy greens | HUS risk: never take antibiotics |
| Listeria monocytogenes | 1 to 4 weeks | Flu-like symptoms | Deli meat, soft cheese, unpasteurized dairy, cold smoked fish | Serious in pregnancy, elderly, immunocompromised |
| Clostridium botulinum | Hours to days | Double vision, droopy eyelids, slurred speech, descending paralysis | Home-canned foods | 911 always: can stop breathing |
Pro tips that matter most
- Most food poisoning resolves in 24 to 48 hours with rest and fluids. An oral rehydration solution (such as Pedialyte) replaces salts better than juice or soda, which can worsen diarrhea.
- Bloody diarrhea means never take antibiotics or anti-diarrheals. If the cause is E. coli O157:H7, both can raise the risk of hemolytic uremic syndrome (HUS), a kidney-failure complication. Let a clinician test and decide.
- Neurological symptoms mean 911. Double vision, droopy eyelids, slurred speech, or descending weakness can be botulism, which can stop your breathing. Call emergency services, do not wait.
- Pregnancy plus Listeria timing is its own rule. Listeria incubates 1 to 4 weeks. Always call your OB or midwife for any flu-like symptoms after deli meat, soft cheese, or unpasteurized dairy, even if they feel mild.
- Over 65 and immunocompromised: lower the threshold. What is home care for a healthy adult can be hospital-level for higher-risk groups. Call sooner rather than waiting it out.
- Save the suspect food. Seal it in a bag in the fridge or freezer. If several people are sick from the same meal, public health can test it and trace an outbreak.
- Report it to public health. In Canada, contact your provincial public-health unit or call 811; in the US, your state health department or foodsafety.gov. Outbreak tracing prevents others from getting sick.
When to call 811 vs urgent care vs 911
- Call 811 or your doctor (call): bloody diarrhea without dehydration, a high fever that will not break after a couple of days, symptoms in a pregnant, over-65, or immunocompromised person, or any case you are unsure about. In Canada, 811 routes you to a nurse line in most provinces.
- Urgent care or the ER (urgent): signs of severe dehydration (no urine for 8 or more hours, dizziness on standing, sunken eyes), bloody diarrhea with those signs, or symptoms after home-canned food.
- Call 911 (emergency): neurological symptoms (double vision, droopy eyelids, slurred speech, descending weakness), severe difficulty breathing, or signs of shock (cold clammy skin, confusion, fainting). Do not drive yourself.
Common mistakes
- Taking Imodium or Pepto-Bismol for bloody diarrhea. Anti-diarrheals trap the toxin and can worsen HUS risk with E. coli O157:H7. Do not use them when there is blood in the stool.
- Taking antibiotics on your own. Antibiotics can also raise HUS risk with O157:H7 and are not needed for most food poisoning. Let a clinician decide based on testing.
- Not saving the suspect food. Tossing it removes the one sample that lets public health confirm the cause and protect others in an outbreak.
- Underestimating Listeria in pregnancy. Mild flu-like symptoms weeks after eating deli meat or soft cheese can be Listeria, which can cause miscarriage or stillbirth. Pregnant patients should always call.
- Using this tool for a child. It is built for adults. For symptoms in children under 18, consult a pediatrician directly; dehydration moves faster in children.
FAQ
Can this tool diagnose my food poisoning?
No. This is an educational pattern-matching tool, not a diagnostic test. It maps your onset time, symptoms, and risk factors to pathogens that commonly cause that picture and suggests an action tier. Only a healthcare provider can diagnose a foodborne illness, often with a stool culture. Use the tool to decide how urgently to seek care, then let a clinician confirm the cause.
How fast does food poisoning usually start after eating?
It depends on the cause. Preformed toxins (Staphylococcus aureus, Bacillus cereus) hit fast, often 30 minutes to 8 hours, usually with vomiting and no fever. Norovirus runs about 12 to 48 hours with watery diarrhea and vomiting. Bacterial causes (Salmonella, Campylobacter, E. coli) range from about 6 hours to 7 days, often with fever. Listeria is the slow outlier at 1 to 4 weeks. Onset timing is one of the strongest clues to the cause.
When should I go to the ER instead of calling my doctor?
Call 911 immediately for neurological symptoms (double vision, droopy eyelids, slurred speech, descending weakness), severe difficulty breathing, or signs of shock. Go to urgent care or the ER for bloody diarrhea, signs of severe dehydration (no urine for 8 or more hours, dizziness on standing, sunken eyes), or a high fever that will not break. For milder but persistent symptoms, call your doctor or 811 (Canada) the same day.
Why should I never take antibiotics or anti-diarrheal medicine for bloody diarrhea?
Bloody diarrhea can signal E. coli O157:H7. Both antibiotics and anti-diarrheal drugs such as Imodium or Pepto-Bismol can raise the risk of hemolytic uremic syndrome (HUS), a type of kidney failure, when O157:H7 is the cause. Let a clinician test and decide. Do not self-treat bloody diarrhea with these medications.
What about children, pregnancy, or older adults?
This tool is for adults only. For symptoms in children under 18, consult a pediatrician directly rather than relying on this tool. Pregnant individuals should call their OB or midwife even for mild flu-like symptoms, because Listeria carries serious pregnancy risk. Adults over 65 and immunocompromised individuals should lower their threshold to seek care, since what is home care for a healthy adult can be hospital-level for higher-risk groups.
Bottom line
Most food poisoning is miserable but self-limiting, and home care with fluids handles it in a day or two. The job of this tool is to flag the patterns that are not: bloody diarrhea (never take antibiotics), neurological symptoms (call 911), Listeria timing in pregnancy, and anything in a higher-risk adult. It is educational, not a diagnosis. For children under 18, consult a pediatrician. Build the prevention layer with the how to read food expiration dates guide and the Family Fridge and Freezer Temperature Log.