The duration of food poisoning primarily depends on the organism or toxin responsible for the illness. A person’s age and physical condition can also influence the duration of food poisoning. In most cases, food poisoning will improve within one to seven days. Severe cases may take longer though, especially if toxins have spread to the bloodstream or other areas of the body. For a fast recovery, sufferers should remain hydrated and seek medical attention if their condition worsens or does not improve within a few days.
The most common causes of food poisoning are bacteria. A few examples of illness-causing bacteria are Clostridium botulinum, Vibrio parahaemolyticus, Staphylococcus aureus, Escherichia coli (E coli), Bacillus cereus, Clostridium perfringens and Shigella. Some of these organisms cause symptoms that will improve within a few days, while others cause more serious illnesses.
Clostridium botulinum is a bacteria that causes a rare disease called botulism. It most commonly occurs after consuming improperly canned foods like chili, corn or soup. To treat botulism, patients are given an antitoxin that prevents the poison from spreading through the bloodstream. Even after treating food poisoning, this condition can take weeks to recover. If left untreated, botulism can lead to paralysis or death.
Another cause of food poisoning that tends to last a long time is Vibrio parahaemolyticus. This bacteria is found in undercooked food and shellfish. After consuming contaminated food, most people will begin showing symptoms, such as fever and vomiting, within 12 to 14 hours. These symptoms typically persist for two to five days. Severe cases might last as long as 10 days.
Food poisoning caused by Staphylococcus aureus, Escherichia coli (E coli), Bacillus cereus, Clostridium perfringens and Shigella usually improves much faster. In the majority of cases, symptoms appear in less than 24 hours and persist for one to two days. These types of food poisoning are rarely serious. Still, if symptoms worsen or fail to improve within three or four days, sufferers should consult their physician.
Ingesting harmful toxins can also lead to poisoning. Examples of toxic foods include many types of wild mushrooms, fish containing high levels of mercury, and pesticide-laden produce. The most common symptoms of food poisoning due to toxic chemicals are nausea, diarrhea and vomiting. If symptoms do not improve within a few days, sufferers should seek medical attention. People suffering from severe symptoms should consult their physician immediately, as certain toxins can be fatal.
Food poisoning can also be caused by viral and protozoal infections. Viral infections like those brought on by consuming contaminated shellfish typically last for two to three days. Protozoal infections like amoebiasis, cryptosporidium enteritis and giardiasis usually develop within a week of consuming contaminated water. These infections produce symptoms that can last from a few days to several weeks. Avoiding possibly contaminated water is one of the best ways of preventing food poisoning due to viral or protozoal infection.
A person’s age can also affect the duration of food poisoning. After being exposed to a toxin or dangerous organism, infants and older adults are more likely to suffer from prolonged bouts of illness. They are also at an increased risk of developing long-term side effects after food poisoning.
Pregnant women and people with compromised immune systems might also develop more serious cases of food poisoning. Since the immune system is less able to fight infection, the duration of food poisoning can be longer in these individuals. The risk of the infection spreading to the bloodstream or affecting major organs is also greater. To avoid potentially dangerous complications, cases that last more than a few days should be examined by a medical professional.