Cornelia Grabmeier holds a BSc in Biology, specialising in neurobiology, from Ludwig Maximilian University of Munich, and is currently pursuing an MSc in Management, Policy Analysis and Entrepreneurship in Health and Life Sciences at Vrije Universiteit Amsterdam. She has completed several research internships, including at the Technical University of Munich Hospital, where she investigated the effects of anaesthetic agents on sleep-wake cycles, and at the Leiden University Medical Centre, where she developed a sandbox for digital health technologies. Cornelia is passionate about making science accessible to a wide audience and inspiring them by communicating fascinating topics. She combines her academic expertise with hands-on research experience to ensure the accuracy and clarity of her work.
Food poisoning: symptoms, causes and treatment explained
Food poisoning is something most people will experience at least once, yet it can still feel alarming when it happens. Sudden nausea, stomach cramps, or diarrhoea can quickly disrupt your day and leave you wondering what went wrong. Understanding the symptoms and how to respond can make a big difference in how quickly you recover. Homed-IQ aims to make reliable health information clear and easy to understand, so you can take the right steps with confidence.
Table of Contents
What is food poisoning?
Food poisoning refers to an illness caused by eating or drinking something contaminated with harmful germs or other toxins. This most often happens due to bacteria, especially when food is not fresh, not properly washed or handled in a sanitary way, not cooked to a safe temperature, or not stored at the correct temperature. It can also be caused by viruses, parasites, or fungi that contaminated food or water (Cleveland Clinic, 2025).
Recognising food poisoning early matters because it helps you manage symptoms effectively, distinguish it from a general upset stomach, and avoid spreading illness to others.
Recognising the symptoms of food poisoning
The symptoms of food poisoning can vary depending on the cause, but the most common ones include:
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Nausea
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Vomiting
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Headache
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Diarrhoea
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Stomach pain
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Fever
Symptoms can begin as soon as 2 to 6 hours after consuming contaminated food or drinks, though some may take a day or two to appear depending on the germ. They usually last 12 to 48 hours and tend to resolve relatively quickly.
Anyone can get food poisoning, but some people are more likely to become ill or develop more severe symptoms. This depends on how much and what type of toxin is consumed, as well as overall health. Young children under 5, adults over 65, pregnant women, and people with weakened immune systems, such as those with chronic illnesses, are typically more vulnerable.
Source: Cleveland Clinic, 2025
Causes of food poisoning
Food poisoning is most commonly caused by:
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Bacteria such as Salmonella, Escherichia coli, and Campylobacter
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Viruses, especially Norovirus
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Parasites
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Toxins
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Molds
Common sources include:
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Food or drinks that are not fresh
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Food or drinks that are not properly washed or filtered
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Food or drinks handled in an unsanitary way
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Food or drinks handled by someone who is infected
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Food that is not cooked to a safe temperature
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Food or drinks not refrigerated or frozen promptly
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Food or drinks not kept at proper temperatures
Source: Cleveland Clinic, 2025
How to treat food poisoning at home
Food poisoning can usually be managed at home, and symptoms often improve within a few days to a week.
The most important step is to stay hydrated, especially if you have diarrhoea or vomiting.
What to do:
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Rest and stay at home
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Drink plenty of fluids (small sips if you feel sick)
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Continue feeding babies, offering smaller, more frequent feeds if needed
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Give small sips of water between feeds for babies on solids or formula
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Eat light foods when you feel able, avoiding fatty or spicy meals
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Use Paracetamol for discomfort (check instructions, especially for children)
Source: NHS, 2024
Speak to a pharmacist if:
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You or your child (over 5) show signs of dehydration (e.g. dark urine or peeing less)
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You are older, have a weakened immune system, or other health conditions
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You need short-term relief from diarrhoea
Seek urgent medical advice if:
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You are concerned about a baby under 12 months
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A child stops feeding or shows signs of dehydration
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Vomiting prevents keeping fluids down
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There is blood in diarrhoea
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Symptoms last longer than 7 days (diarrhoea) or 2 days (vomiting)
At Homed-IQ, we aim to keep you informed with clear, reliable guidance and offer free information materials to help you recognise symptoms, manage them safely at home, and know when to seek further care.
Source: NHS, 2024
Staying safe: preventing food poisoning
Follow four key food safety steps: clean, separate, cook, and chill.
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Clean: Wash hands, surfaces, and fresh produce regularly
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Separate: Keep raw meat, seafood, and eggs away from ready-to-eat foods
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Cook: Ensure food is cooked thoroughly using the right temperature
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Chill: Refrigerate perishable food promptly and keep it at safe temperatures
Additional tips:
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Avoid leaving food out for too long at room temperature
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Store raw foods securely to prevent leaks and contamination
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Reheat food thoroughly
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Thaw frozen food safely (in the fridge, cold water, or microwave)
Source: CDC, 2025
Frequently asked questions about food poisoning
What is the difference between food poisoning and a stomach virus?
Food poisoning and viral gastroenteritis, often called the “stomach flu,” can feel very similar because they share symptoms like diarrhoea, nausea, and vomiting.
The main differences are how quickly symptoms start and how long they last. Food poisoning usually begins quickly, often within 2 to 6 hours after eating contaminated food, and tends to pass relatively fast. In contrast, a stomach flu typically develops after 24 to 48 hours and may last a bit longer.
Food poisoning is often linked to a recent meal, while a stomach virus is more likely to spread from person to person, for example within households or communities.
Source: Cleveland Clinic, 2022
When should you see a doctor for food poisoning symptoms?
Most cases resolve on their own, but medical attention is important if you experience:
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You are concerned about a baby under 12 months
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A child stops feeding or shows signs of dehydration
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Symptoms in young children, older adults, or pregnant individuals
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Vomiting prevents keeping fluids down
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High fever
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There is blood in diarrhoea
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Symptoms last longer than 7 days (diarrhoea) or 2 days (vomiting)
If in doubt, it’s always better to seek professional advice. Early care can prevent complications and help you recover more quickly.
Source: NHS, 2024




