How long before bad eggs make you sick?

October 27, 2025 •

4 min read

Symptoms of food poisoning from a contaminated egg, most commonly caused by Salmonella bacteria, can appear anywhere from 6 hours to 6 days after consumption. The incubation period varies depending on the amount of bacteria ingested and your individual health, but understanding this timeline is crucial for assessing your risk and knowing when to seek help.

Quick Summary

The incubation period for food poisoning from bad eggs can range from hours to days, with symptoms typically appearing within 6 to 72 hours due to bacteria like Salmonella. The severity and duration of illness depend on individual health and bacterial load.

Key Points

Symptom Onset: Symptoms of food poisoning from bad eggs can appear between 6 hours and 6 days after ingestion, with 12 to 72 hours being the most common timeframe.
Primary Bacteria: Salmonella is the most frequent cause of bacterial food poisoning associated with eggs, leading to symptoms like diarrhea, fever, and abdominal cramps.
Influencing Factors: The severity and speed of illness depend on the bacterial load, an individual's immune system, and age.
High-Risk Groups: Young children, the elderly, and those with compromised immune systems are more vulnerable to severe illness from contaminated eggs.
Prevention is Key: Proper refrigeration, cooking eggs thoroughly until the yolk is firm, and avoiding raw egg products are crucial preventive measures.
Seek Medical Help: Consult a doctor if symptoms like high fever, bloody stools, or signs of severe dehydration develop.
Freshness Test: Use a float test to check an egg's age, but a foul odor is the most reliable sign of a rotten egg.

Understanding the Incubation Period for Egg-Related Illness

When you ingest a contaminated egg, the timeline for developing symptoms can be surprising. Unlike immediate reactions to a rotten taste, foodborne illness is caused by bacterial growth within your body. The most common culprit is Salmonella, which has a variable incubation period.

The Typical Timeline for Salmonella Symptoms The majority of people who become sick from Salmonella will experience symptoms within 6 to 72 hours (3 days) after consuming a contaminated egg. However, this is not an exact science. In some cases, the onset of illness can be as quick as 6 hours or take as long as 6 days to manifest. This wide range is why some people might not immediately connect their symptoms to a meal they ate days earlier.

Factors Influencing Sickness from Bad Eggs

Several factors can influence the timeline and severity of illness after eating a contaminated egg. The bacterial load—the amount of harmful bacteria ingested—is a primary factor. A higher concentration of bacteria will typically lead to a quicker onset of more severe symptoms. Your overall health and age also play a significant role. Vulnerable populations, such as young children, older adults, and those with weakened immune systems, are at a higher risk for more severe illness and quicker symptom onset.

Amount of bacteria: A larger dose of Salmonella can overwhelm the body faster.
Individual health: A robust immune system might fight off a low bacterial load without causing noticeable symptoms.
Age: Infants, young children, and older adults have less resilient immune systems.
Cooking method: The way an egg is prepared directly affects the risk. Raw or undercooked eggs, like those in homemade mayonnaise, increase risk, while thoroughly cooked eggs are safer.

Symptoms of Food Poisoning from Eggs

Knowing the signs of illness is crucial. Food poisoning from bad eggs can feel very similar to a bad stomach flu, making it easy to misdiagnose. The key symptoms are related to gastrointestinal distress but can also include more general systemic signs.

Common Symptoms:

Diarrhea: Often watery, and in severe cases, may contain blood.
Fever: Your body's attempt to fight the infection.
Stomach cramps and abdominal pain: The bacteria irritate the intestinal lining.
Nausea and vomiting: Your body's way of purging the toxin.
Headache: A common symptom accompanying fever and dehydration.

When to Seek Medical Attention

While most cases of food poisoning from eggs resolve on their own within 4 to 7 days, certain symptoms warrant immediate medical care. Dehydration is a significant risk, especially if vomiting and diarrhea are persistent.

Red Flags for Severe Illness:

High fever (above 102°F)
Persistent vomiting and diarrhea (lasting more than 2 days)
Signs of dehydration, such as dark-colored urine, dry mouth, or dizziness.
Blood in your stool
Weakened immune system or chronic illness

How to Prevent Sickness from Eggs

The best way to deal with bad eggs is to avoid them altogether. Proper handling and storage can significantly reduce your risk of contracting a foodborne illness.

Egg Safety: A Quick Comparison


Aspect	Safe Egg Handling	Risky Egg Handling
Storage	Refrigerate eggs at or below 40°F (4°C).	Leaving eggs out at room temperature for extended periods.
Preparation	Cook eggs until both the yolk and white are firm. Use pasteurized eggs for dishes with raw egg.	Eating raw or undercooked eggs (e.g., runny yolks, homemade dressings).
Contamination	Use only clean, uncracked eggs. Wash hands and surfaces after handling raw eggs.	Using cracked or dirty eggs; cross-contaminating with raw egg.
Timeline	Consume eggs well before the 'sell by' date, typically within 3-5 weeks.	Eating eggs past the 'sell by' or 'pack' date without a freshness check.

The Float Test and Other Freshness Checks

Beyond looking for cracks or a foul odor, the float test is a simple way to determine an egg's age. Place the egg in a bowl of water. A fresh egg will sink and lie flat on its side. As an egg ages, the air cell inside grows, causing the egg to stand on one end. A truly spoiled egg will float because the air cell is large enough to make it buoyant. While a floating egg is a strong indicator of spoilage, it doesn't guarantee the presence of bacteria, just that it's no longer fresh. Always combine multiple senses—smell, sight, and the float test—when in doubt. For more information on egg safety, visit the official site of the FDA at FoodSafety.gov.

Conclusion: Prevention is the Best Cure

The time it takes for a bad egg to make you sick varies, but typically falls within 6 hours to 6 days for a Salmonella infection. The best course of action is to prevent the issue entirely through careful handling, storage, and cooking. By staying vigilant and knowing the signs of food poisoning, you can protect yourself and your family. In most cases, the illness is mild and self-limiting, but for vulnerable individuals or those with severe symptoms, medical attention is a necessity.

Frequently Asked Questions

Symptoms of food poisoning from a bad egg can begin as quickly as 6 hours after consumption, but often take 12 to 72 hours to appear.

The first signs of food poisoning often include stomach cramps, nausea, diarrhea, and fever, resembling a common stomach flu.

Thoroughly cooking an egg kills most harmful bacteria, like Salmonella. However, if an egg is contaminated and not cooked to a safe internal temperature (yolk and white are firm), the risk of illness remains.

An expired egg might simply be older but safe to eat if stored properly. A 'bad' or spoiled egg contains harmful bacteria, often evidenced by a foul sulfurous smell or a floating test, and should never be eaten.

Most cases resolve on their own. Stay hydrated by drinking plenty of fluids. For severe symptoms like high fever or bloody diarrhea, seek medical attention.

The putrid, sulfurous smell is a clear sign that an egg is rotten and should be discarded. While it indicates spoilage, the specific bacteria causing food poisoning, like Salmonella, do not typically have a smell.

Symptoms from a Salmonella infection generally last for 4 to 7 days. Most healthy individuals recover without specific treatment during this time.