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What Causes Food Poisoning? What Are The Symptoms And Treatments?



Food poisoning is a general term for the umbrella of illnesses that are caused by consuming contaminated food. In most cases, people recover naturally. However, some forms of food poisoning are dangerous. Weaker sections of the population may also be more at risk of developing complications. Food poisoning is also especially dangerous in children who may develop dehydration as a result of water loss.




What causes food poisoning?


When the food you consume has been contaminated with bacteria, fungi, parasites or viruses, either the contaminant organisms themselves or the toxins produced by them cause the symptoms of food poisoning. This is generally a mechanism for the body to eliminate toxic substances from your digestive system through vomiting or diarrhoea.


What causes food to be contaminated?


  • Old or decaying food
  • Unwashed consumption
  • Bad handling in the supply chain
  • Improper cooking
  • Improper storage


Food poisoning is also contagious from an infected person if someone comes in contact with the germs.


What is traveller’s diarrhoea?


When travelling abroad, your body is exposed to new disease-causing organisms than your body is used to. This makes your immune system less prepared and you, more likely to get food poisoning. This is generally referred to as a traveller’s diarrhoea.


What are the types of food poisoning?


There are 250+ types of food poisoning caused by various organisms and toxins. Some commonly linked causes include:

  • Salmonella - usually from raw eggs and uncooked poultry or contamination from bird droppings
  • coli - usually from uncooked meat and raw vegetables
  • Listeria - from cheese, raw sprouts,
  • Norovirus - from uncooked food, sometimes referred to as stomach flu
  • Hepatitis A - from contaminated water, ice, shellfish, fresh vegetables
  • aureus - usually hand-to-food contamination
  • Campylobacter - uncooked poultry, meat, eggs raw milk or contaminated water
  • Shigella - usually from uncooked vegetables, shellfish, mayonnaise-based salads etc.


What are the signs and symptoms of food poisoning?


Depending on the type of food poisoning, your symptoms may start affecting you within a few hours or a few days or in some cases, even a few weeks. This is the time taken for the infection to grow enough to become toxic. Some of the common symptoms include:

  • Loose, watery stools
  • Increased bowel movement
  • Feeling like vomiting or vomiting
  • Fever
  • Headache
  • General body weakness


The symptoms generally pass within 12 to 48 hours. However, if you have a weakened immune system or a serious infection, it can last longer and may require medical attention.


What symptoms require medical attention?

Any nervous system symptoms require immediate care. These include:

  • Blurry vision
  • Headache
  • Paralysis
  • Tingling or numbness in the skin


Anyone showing signs of dehydration also requires immediate care so that the dehydration does not affect other parts of the body. This is especially true for children where severe dehydration can be life-threatening. Since children have lesser body weight and overall water in their body, their dehydration worsens fast. The signs of dehydration include:

  • Feeling extremely thirsty
  • Dryness in mouth
  • Less quantity or frequency of urination
  • A darker colour of urine
  • Skin takes time to revert back to normal when pinched and released
  • Sunken eyes or cheeks
  • No tears when crying


Any of the more serious symptoms like the following also require attention immediately:

  • Changes in the mental state like confusion
  • Very high fever
  • Very frequent vomiting
  • >6 times of stool passing per day
  • >3 days of diarrhoea
  • Severe pain
  • Black tarry or dark red stools
  • Stool with pus


How is food poisoning diagnosed?


Based on your symptoms, your doctor may ask you for a blood or stool sample for tests. This can usually determine the cause of the food poisoning, but such measures may be recommended only if the condition is serious and requires intervention.


How do you prevent food poisoning at home?


Some hygiene practices can help in preventing food poisoning at home. These include:

  • Washing hands before touching food
  • Washing utensils and surfaces often
  • Keeping raw food separate from cooked food
  • Cooking food to a safe temperature
  • Proper refrigeration
  • Throwing out food when in doubt
  • Wash vegetables and fruits before consumption
  • Avoiding raw or uncooked food


How is food poisoning treated?


In most cases, food poisoning does not require treatment and resolves itself within 48 hours. However, in more serious situations, your doctor may recommend appropriate treatment based on the kind of organism causing your infection. If you are suffering from dehydration or low nutrition level, your doctor may correct it with drinkable solutions or intravenous fluids. Anti-diarrhoea medication is generally avoided as it usually prolongs the illness.


Medanta Medical Team
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