Food Hygiene and Safety

What is Food Poisoning? Types, Causes, Symptoms & Treatment

Ricky Kambray
Ricky Kambray

Have you ever experienced an upset stomach after eating out or trying a new dish? Chances are, you might have had food poisoning! So, what is food poisoning? It is a common illness caused by consuming contaminated food or drink, resulting in uncomfortable symptoms such as nausea, vomiting, and diarrhoea.

But don’t worry. You can easily prevent food poisoning by practising good hygiene and handling practices. From washing your hands to cooking your food thoroughly, you can take several easy steps to keep yourself safe and healthy.

So, in this blog, we will explore the world of food poisoning – from its causes and types to its symptoms, treatment and prevention. So let’s learn how to stay safe and enjoy your favourite foods without any worries!

Besides, want to keep your food safe and healthy? Visit our latest blog post on the 4 C’s of Food Safety and learn how to prevent foodborne illnesses!

3D illustration of cartoonish germ

What is Food Poisoning?

Food poisoning, often known as foodborne illness, is caused by contaminated food or liquids. Contamination can occur when harmful bacteria, viruses, parasites, toxins, or chemicals are present in the food.

The poisoning can be mild or severe, and in some cases, it can be life-threatening. Therefore, it is important to know the causes, types, symptoms, and treatment to prevent it from happening and address it if it occurs.

Now let’s explore some common causes.

Causes of Food Poisoning

The causes of food poisoning refer to the germs or substances that make the meal harmful and make people sick. These are the following:

  • Bacteria (e.g. Salmonella, E. coli, Campylobacter)
  • Viruses (e.g. Norovirus, Hepatitis A)
  • Parasites (e.g. Cryptosporidium, Giardia)
  • Toxins produced by bacteria (e.g. Botulinum toxin)
  • Chemical contaminants (e.g. pesticides, heavy metals)
  • Allergens (e.g. peanuts, shellfish)
  • Improper food handling or preparation (e.g. cross-contamination, inadequate cooking or refrigeration)

These causes are the underlying factors that lead to the different types of food poisoning. Understanding the causes can help identify and prevent the different kinds of food poisoning.

Discover the top high-risk foods and learn how to prevent foodborne illnesses by reading our blog post What are High-Risk Foods.

Close-up of microscopic germs and pathogens

Types and Symptoms of Food Poisoning

The types of food poisoning are different illnesses caused by various microorganisms, which lead to varying symptoms.

Here is a chart that shows the various causes of food poisoning, symptoms, the time it takes for symptoms to appear, and common sources of contamination:

Causes of food poisoningSymptomsHow soon symptoms start Where it’s found
Ascaris lumbricoidesCoughing, nausea, vomiting etc.Rarely causes noticeable symptomsProduce grown in contaminated soil
AstrovirusDiarrhoea, vomiting, nausea, anxiety, headache  4-5 daysContaminated water
CampylobacterDiarrhoea (often bloody), fever, stomach cramps2-5 daysRaw or undercooked chicken, unpasteurised milk, contaminated water
E. coliSevere stomach cramps, diarrhoea (often bloody), vomiting3-4 daysRaw or undercooked beef, raw sprouts, unpasteurised milk, contaminated water etc.
Hepatitis A virusStomach pain (especially in the upper right quadrant), nausea, vomiting, diarrhoea, jaundice (yellowing of your skin and eyes) etc.15-50 daysFrozen berries, frozen vegetables, contaminated water, improper food handling etc.
SalmonellaDiarrhoea (can be bloody), fever, stomach cramps, vomiting6 hours to 6 daysRaw or undercooked poultry, raw fruits and vegetables, eggs, contaminated water
Staphylococcus aureusNausea, vomiting, stomach cramps, diarrhoea30 minutes-8 hoursPuddings, sliced meats, and food not handled or stored at proper temperatures.
ListeriaMiscarriage, premature delivery, or life-threatening infection of the newborn. Call your doctor immediately if you have a fever and feel exhausted and achy.1-4 weeksUnpasteurised dairy (like milk and soft cheeses), melon, raw sprouts etc.
NorovirusFeeling sick (nausea), being sick (projectile vomiting), diarrhoea (watery), headache, high temperature and aching arms and legs. (Resource NHS)24 to 48 hoursOysters and other shellfish, lettuce and leafy greens, contaminated water, improper food handling etc.


Food poisoning symptoms vary by contaminant type and infection severity. Common and severe symptoms are as follows.

Symptoms of Food Poisoning

It’s unlikely that you’ll overlook the symptoms. Typical signs include:

  • Abdominal cramps
  • Diarrhoea
  • Nausea
  • Vomiting
  • Loss of appetite
  • Mild fever
  • Weakness
  • Headache

It can sometimes cause severe symptoms such as:

  • Diarrhoea lasting more than three days
  • Fever higher than 102°F (38.9°C)
  • Trouble seeing or speaking
  • Severe dehydration, with symptoms like dry mouth, little or no urine, and difficulty keeping fluids down
  • Bloody urine

When to See a Doctor

In most cases, you can treat yourself or your child at home if you get food poisoning. Symptoms typically subside within a week.

The most vital thing is to stay hydrated by drinking enough fluids, such as water or squash. However, it’s important to see a doctor in certain situations, such as

Infants and Children

Dehydration from vomiting and diarrhoea can be dangerous for infants and children. Inform your child’s healthcare provider if your child shows any of the following symptoms:

  • Unusual changes in actions
  • Extreme thirst
  • Diarrhoea lasting more than a day
  • Vomiting constantly
  • Little or no urination
  • Weakness
  • Dizziness
  • Stools that have blood or pus
  • Black stools
  • Severe stomach or rectum pain
  • Fever in children under two years of age
  • Fever of 102°F (38.9°C) or higher in older children
  • History of other medical issues.


Adults should seek medical attention or seek emergency care if any of the following symptoms occur:

  • Nervous system symptoms like blurry vision, muscle weakness, or tingling skin.
  • Changes in thinking or actions.
  • Fever of 103°F (39.4°C) or higher.
  • Frequent vomiting.
  • Diarrhoea lasting more than three days.
  • Signs of dehydration like dry mouth, excessive thirst, little or no urination, severe weakness, and dizziness.

Remember that pregnant women and older adults should consult their doctor immediately if they have a fever or other flu-like symptoms.

Happy doctor holding a clipboard with patients

Treatment of Food Poisoning

The treatment relies on the severity of the illness, the specific cause of the poisoning, and the affected persons’ overall health.


Staying hydrated is the most important treatment. To restore fluids lost due to diarrhoea and vomiting, drink plenty of fluids such as —

  • water,
  • clear broth,
  • or electrolyte drinks.


Resting can help your body recover. Avoid hard activities until you feel better.


Medications, such as anti-diarrheal or anti-nausea drugs, may be used to treat certain symptoms. However, speaking with a doctor before taking any medications is important.


Most cases of food poisoning do not need antibiotics since they can worsen the illness, but antibiotics may be necessary for severe cases of bacterial attack.


In severe cases, hospitalisation may be necessary for —

  • close monitoring,
  • intravenous fluids,
  • and treatment with antibiotics.

First and foremost, the best way to treat food poisoning is to prevent it from happening in the first place.

Prevention text written on clipped white paper

How to Prevent Food Poisoning?

Explore some preventive ways:

  • Wash your hands well before and after handling raw meat, poultry, or seafood.
  • Cook foods to the right temperature to kill bacteria and other harmful germs.
  • Do not use the same cutting boards and utensils for raw and cooked foods to avoid cross-contamination.
  • Store food properly in the freezer to prevent decay.
  • Avoid eating undercooked or raw meat, poultry, seafood, and eggs.
  • Avoid eating unpasteurised dairy products, juices, or cider.
  • Wash fruits and veggies well before eating or cooking.
  • Maintain good hygiene in the kitchen when handling food.

Wrapping Up

Having proper knowledge of the question, “what is food poisoning” and understanding the causes, symptoms, and prevention methods, you can keep yourself and your loved ones safe from the risks of food poisoning. Always handle food carefully and trust your instincts if something seems wrong. Stay safe, and enjoy your meals!


What to eat after food poisoning?

Stick to small, light, easily digestible meals such as plain rice, toast, bananas, boiled potatoes etc., after food poisoning.

What is the most common type of food poisoning?

Bacteria such as Salmonella, E. coli, and Campylobacter cause the most common type of food poisoning and can be found in undercooked poultry, meat, eggs, and dairy products.

What does food poisoning feel like?

Diarrhoea lasting longer than three days, a fever over 102°F, constant vomiting, and signs of dehydration such as little or no urine, dry mouth etc., are the common symptoms of food poisoning.


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Ricky Kambray

Hey this is Ricky Kambray an award-winning first-aid trainer with over 20 years of healthcare and teaching expertise. Highly certified general nurse regularly appears in the press discussing accident prevention and first aid advice.