Food borne diseases can be divided into food infection and food poisoning. The popular media tends to describe all food-related illnesses as "food poisoning", but strictly speaking, this is incorrect.

  Food poisoning is caused by consuming foods that contain toxins. These toxins can be produced by micro organisms, can occur naturally in the food (for example, in certain mushrooms) or can be a contaminant.

  Toxins directly affect the biological reactions taking place in the body. At sufficiently high concentrations, the effects are acute and take place a few hours after consumption. Symptoms can include nausea and vomiting. The toxins can have various origins, but the two most well known bacterial toxins are produced by Staphylococcus aureus and Clostridium botulinum .

  Certain toxins e.g. mycotoxins have serious long-term effects even at small concentrations.Most of these toxins are resistant to heat, so they are not eliminated by cooking.

  A food borne infection is caused by an infectious pathogens (micro organisms that cause infections) in the food. These micro organisms multiply in the intestine. Furthermore these micro organisms release toxins that invade and damage the epithelium cells. The consequences are stomach ache and diarrhoea within some hours or several days after eating the contaminated food. After a few days these symptoms disappear, but one can still excrete the germ with the stools. Such a person is called a healthy carrier. By bad (toilet) hygiene one can contaminate food and other people.

  The bacteria causing most food infections are Salmonella , Campylobacter and E. coli . Viruses also cause food borne infections. Most food borne infections occur during the summer, because the growing conditions for the bacteria are better. In most cases the food infection is quite mild, most people only have diarrhoea. Older people, small children or people with a weak resistance are most severely affected.

  Proper heating of food can prevent food borne infections. Almost all non-spore forming bacteria are killed at temperatures above 70 °C.

  Although most food borne infections occur in the home, outbreaks in restaurants often get more attention because they tend to affect larger numbers of people.