Overview
Foodborne illness is an infection or irritation of the digestive system caused by contaminated food or drinks. The contamination may come from germs such as bacteria, viruses, and parasites, or from toxins made by some germs. Symptoms can begin within hours or may take days, depending on the cause. Illness ranges from mild and short-lived to severe and sometimes life-threatening.
Key Symptoms
Common symptoms include diarrhea, nausea, vomiting, stomach pain or cramps, and loss of appetite. Some people also develop fever, headache, body aches, or feel very weak. Bloody diarrhea, severe vomiting, and signs of dehydration are more concerning. Symptoms and timing vary depending on the specific germ or toxin involved.
Causes and Risk Factors
Food can become contaminated during growing, processing, transport, storage, or preparation. Higher-risk foods include raw or undercooked meat, poultry, eggs, seafood, unpasteurized milk products, and raw produce that has not been washed well. Poor hand hygiene, unsafe water, cross-contamination in the kitchen, and keeping food at unsafe temperatures increase risk. Travel, outbreaks in community settings, and eating food from unsafe sources can also raise the chance of getting sick.
Who Is Affected
Anyone can get foodborne illness. However, infants and young children, older adults, pregnant people, and people with weakened immune systems are more likely to develop severe illness or complications. People with certain long-term health conditions may also have a harder time recovering. In some regions, limited access to clean water and food safety systems increases exposure.
Prevention
Wash hands, utensils, and surfaces before and after handling food. Keep raw meat, poultry, seafood, and eggs separate from ready-to-eat foods to avoid cross-contamination. Cook foods thoroughly, refrigerate perishable items promptly, and avoid leaving food at room temperature too long. Wash produce, use safe water when possible, and be cautious with unpasteurized products and raw or undercooked animal foods.
Diagnosis and Tests
A healthcare professional may ask about symptoms, foods recently eaten, travel, and whether other people are sick. Some cases can be identified based on symptoms and timing alone, while others may need stool tests or blood tests to look for the cause or check for complications. Testing is more likely when illness is severe, prolonged, involves blood in the stool, or happens during an outbreak. In some situations, public health authorities may investigate to find the source.
Treatment Categories
Treatment depends on the cause and how sick the person is. Replacing fluids is very important because vomiting and diarrhea can lead to dehydration. Some people may need medical care for testing, monitoring, or treatment in a clinic or hospital, especially if symptoms are severe or they belong to a higher-risk group. Not every foodborne illness is treated the same way, so professional advice can matter.
Diet and Lifestyle
When symptoms are active, many people do better with small sips of fluid and simple foods as tolerated. It may help to avoid alcohol and foods that seem to worsen nausea or diarrhea until recovery. Rest can support recovery, and returning to normal eating can happen gradually. Good kitchen hygiene at home also helps protect other household members.
When to Seek Medical Care
Seek medical care if symptoms are severe, last more than a few days, or keep returning. Get advice sooner for infants, older adults, pregnant people, and people with weakened immune systems. Medical care is also important for blood in the stool, high fever, severe abdominal pain, or signs of dehydration such as very little urination, dizziness, confusion, or extreme weakness. If you think illness may be linked to a shared meal or outbreak, tell a healthcare professional.
When It May Be an Emergency
Emergency help may be needed for trouble staying awake, fainting, seizures, difficulty breathing, severe dehydration, or signs of shock. Emergency evaluation is also important for persistent vomiting that prevents keeping fluids down, severe confusion, or very severe abdominal pain. In babies and young children, fewer wet diapers, no tears when crying, unusual sleepiness, or a sunken soft spot can be urgent warning signs.