Food poisoning is an acute condition that develops after eating food or drinking water that contains bacteria, viruses, parasites, or toxins. It usually affects digestion and causes general weakness. Doctors often call it acute intestinal infection or foodborne illness.
Food poisoning symptoms
Common symptoms include:
- nausea;
- vomiting;
- diarrhea;
- stomach pain, often cramping;
- fever;
- weakness.
Symptoms may appear within a few hours after eating, and sometimes the next day or later, depending on the cause. In most cases food poisoning resolves on its own within 1–3 days, sometimes taking up to a week.
What causes it
Typical causes are undercooked meat and poultry, raw or poorly washed vegetables and herbs, dairy and egg dishes that were not stored properly, seafood, cooked dishes left in the warmth, dirty hands and utensils, and unsafe water. The source often cannot be identified, because people do not always know what caused it. Similar symptoms can occur with other infections, for example rotavirus, and in the early stages of hepatitis A and typhoid fever, so prolonged or unusual symptoms should be seen by a doctor.
Why it can be dangerous
The main risk is dehydration from vomiting and diarrhea. It develops faster in children, older people, pregnant women, people with weakened immunity, and in hot weather. Signs of dehydration include strong thirst, a dry mouth, dark urine or passing urine rarely, dizziness, and weakness. In small children, look for no tears, no wet diapers, and unusual sleepiness. Severe infections can also come with blood in the stool and a high fever.
What to do at home
Mild cases can be managed at home:
- Drink often, in small sips: water, weak tea, or oral rehydration solutions from a pharmacy. Prepare the solutions strictly according to the package instructions.
- Rest. Your body needs energy to recover.
- Return to food gradually once the nausea passes: plain, low-fat, unspiced food in small portions.
- Do not take antibiotics or anti-diarrheal medicines without a doctor's advice. Do not give them to children without a doctor.
The medicines and doses that suit you or your child are chosen by a doctor.
When to see a doctor
See a doctor (a general practitioner, gastroenterologist, infectious disease specialist, or a pediatrician for a child) if:
- vomiting lasts more than two days or diarrhea lasts more than a week;
- there are signs of dehydration;
- there is blood in the stool;
- the fever is high or lasts several days;
- the patient is a young child, an older person, a pregnant woman, or someone with a chronic illness.
Call an ambulance at 112 if there is vomiting of blood or green vomit, severe stomach pain, a severe headache with a stiff neck, trouble breathing, confusion, or loss of consciousness. You can find suitable doctors in the Doctors block further down this page.
How to prevent food poisoning
There is no vaccine against ordinary food poisoning, because many different germs cause it. Prevention rests on safe food handling, as the WHO recommends:
- wash your hands before eating and cooking, after the toilet, and after handling raw meat;
- keep raw and cooked foods apart and use separate boards and knives for meat;
- cook meat, poultry, eggs, and fish thoroughly;
- store food at safe temperatures: do not leave cooked dishes in the warmth for long, and refrigerate leftovers;
- drink water from safe sources and wash vegetables and herbs with clean water.
Travelers should be more careful with street food and dishes that sat for a long time without refrigeration, especially in hot weather, when bacteria multiply faster.
