AT A GLANCE: Here are key things you will learn about food poisoning from Kristine Ortega-Fonte, MD, a family physician at Atrium Health, in this article:
- Food poisoning can be caused by bacteria, viruses, parasites or chemicals.
- Symptoms of food poisoning can begin within hours of eating contaminated food or take days to appear.
- Preventing dehydration is one of the most important steps when recovering from food poisoning.
- Certain people, including young children, older adults, patients who are pregnant and people with weakened immune systems, are at higher risk for serious complications from food poisoning.
- Proper food storage, handwashing and avoiding cross-contamination can help prevent food poisoning.
- Contact your doctor if you have signs of dehydration, bloody vomit or stool, a high fever or severe abdominal pain.
Food poisoning—also called foodborne illness—can turn a meal into an unpleasant experience, with symptoms ranging from nausea and vomiting to diarrhea and abdominal pain. In some cases, symptoms are mild and improve on their own. In others, people can become seriously ill, particularly when vomiting or diarrhea leads to dehydration.
Contaminated food may contain bacteria, viruses or parasites, while some illnesses result from toxins or chemicals. Recognizing when symptoms can be managed at home—and when medical care is needed—is especially important. People who are older, very young, pregnant or have weakened immune systems can be more vulnerable to complications and may need to contact their health care professional sooner.
The AMA's What Doctors Want Patients to Know™ series gives physicians a platform to share what they want patients to understand about today's healthcare headlines.
In this installment, Kristine Ortega-Fonte, MD, a family medicine doctor with Atrium Health Floyd, which is part of Advocate Health, explains what patients should know about food poisoning, including how to recognize concerning symptoms, prevent dehydration and reduce the risk of getting sick.
Advocate Health is part of the AMA Health System Member Program, which provides enterprise solutions to equip leadership, physicians and care teams with resources to help drive the future of medicine.
Food poisoning can cause a range of digestive symptoms
“Food poisoning is a type of foodborne illness and common symptoms can include nausea, vomiting, belly pain and diarrhea when contaminated food is consumed. Some patients may get a fever,” said Dr. Ortega-Fonte.
“Signs of foodborne illness may begin as quickly as one hour after eating contaminated food or be delayed,” she said, noting that “symptoms and complications can last weeks, dependent on the root cause.”
Germs and contaminants can cause food poisoning
“Food poisoning is caused by eating food that contains different germs,” Dr. Ortega-Fonte said. “These germs are the bacteria, viruses or parasites that contaminate food and make us sick.”
“Some of these germs can be spread from person to person, while others cannot,” she said.
Some people are at higher risk of serious complications
“Older adults and young children can be at higher risk for greater complications,” said Dr. Ortega-Fonte. “Patients with weakened immune systems and patients who are pregnant are also at higher risk.”
“If they fall into these categories and experience symptoms, they need to go ahead and get in touch with or reach out to their doctor so they can get ahead of what’s happening and keep their symptoms to a minimum.”
“Your primary care clinician knows you and your medical history,” said Dr. Ortega-Fonte. “For example, if you are undergoing treatment for cancer or have other medical problems that cause a weakened immune system, you need to be extra cautious because you do not want to get dehydrated.”
Treating food poisoning begins with asking questions
“Treating food poisoning starts with the clinical diagnosis and the patient history,” Dr. Ortega-Fonte said. “But if your physician feels there may be something else going on that can be treated, then we’ll run as many tests as we need to find the cause.”
“Tests are not usually done unless your doctor wants to check if you're dehydrated or they're trying to figure out the cause of the food poisoning,” she explained. “In most cases, clinicians are more likely to ask questions to arrive at a diagnosis.”
“When I interview a patient, I want to know how long this has been going on—when did the symptoms start? And then we also ask if you have traveled to certain countries, including ones that are endemic for certain diseases,” Dr. Ortega-Fonte said. “I will also ask if you have done some camping or if you have gone to certain bodies of water. All of this is important information that helps us figure out what’s going on.”
“Your treatment plan will focus on your symptoms, and your doctor will work with you to keep you from getting dehydrated,” she said, noting that “blood tests or stool tests may not be necessary.”
Most people recover from food poisoning at home
“Many people do not need any treatment because their symptoms will get better on their own,” said Dr. Ortega-Fonte. “But depending on the patient's situation, especially looking into that category of special populations, your doctor might recommend getting fluids through an IV, a thin tube that goes into the vein.”
“People with a lot of diarrhea or vomiting might need IV fluids to treat or prevent dehydration,” she noted. “If you are very sick and there is concern for an invasive infection, you might get antibiotics to help treat the infection. But most people do not need antibiotics, even if they have a bacterial infection.”
Preventing dehydration is the top priority at home
“There are a lot of things you can do on your own at home to treat food poisoning,” Dr. Ortega-Fonte said. “The main thing is to prevent dehydration. You need to drink lots of fluids to stay hydrated.”
“When you are vomiting or having diarrhea, your body loses both salt and water. So, drinking fluids that contain electrolytes can help replace what your body has lost,” she explained. “Examples include oral rehydration solutions like the ones you see in grocery stores or drug stores. Broth is also helpful.”
“You should also try to eat small, mini meals that do not have a lot of fat in them and are bland, so they don't upset the tummy,” Dr. Ortega-Fonte said. “Good choices are potatoes, noodles, rice, oatmeal, crackers, bananas, soup and boiled vegetables.”
“Popsicles can be really helpful for kids,” she added. “For patients who have an issue keeping water down, ice may be helpful.”
“The main thing is we want to prevent you from being dehydrated. And then, of course, if you feel tired, you must get some rest,” Dr. Ortega-Fonte emphasized.
Certain symptoms warrant a call to your doctor
While most symptoms that are mild can be managed at home, Dr. Ortega-Fonte said there are signals that a patient should seek medical attention. These include:
- More than six runny bowel movements within a 24-hour period.
- Blood in your vomit or stool.
- Fever higher than 101.3ºF for more than a day.
- Severe stomach pain.
- Signs of dehydration.
“How do you know if you are dehydrated? The symptoms include lots of very watery diarrhea, feeling tired and excessive thirst,” Dr. Ortega-Fonte explained. “There's a mechanism in the body that tells us when we are dehydrated. You are thirsty. You have a dry mouth. You get muscle cramps. You feel dizzy or confused, or your urine is dark.
“Those are signs to look for,” she added. “Also, if you have not urinated for more than five hours, you need to get in touch with your doctor right away.”
Simple food safety practices can reduce risk of food poisoning
“To reduce your chance of getting food poisoning or spreading germs that can cause food poisoning, of course you need to wash your hands after changing diapers, going to the bathroom, blowing your nose, touching animals, touching raw meat or taking out the trash,” Dr. Ortega-Fonte said. “Also, stay at home from work or school when you are sick because some cases can be contagious.”
She also emphasized other food safety practices. They include:
- Do not drink unpasteurized milk or food made with it.
- Wash fruits and vegetables well before eating them.
- Keep your refrigerator colder than 40º F and the freezer below 0º F.
- Cook meat and seafood until at least the safe minimal temperature.
- Cook eggs until the yolk is firm.
- Wash hands, knives and cutting boards after they touch raw food.
- Watch for cross-contamination.
“Most importantly, wash your hands often,” Dr. Ortega-Fonte emphasized.
Improperly stored foods can cause fried rice syndrome
“Fried rice syndrome has been a topic in the news recently and one that people should be aware of when discussing foodborne illness,” Dr. Ortega-Fonte said. “Fried rice syndrome is a type of food poisoning that is caused by a bacteria called Bacillus cereus.”
“The term fried rice is used because it's most commonly from fried rice, but you can also get it from other foods such as pasta and casseroles,” she explained. “Usually this happens when these foods are left out at room temperature for a prolonged period of time.
“That is when the bacteria’s spores can multiply. The spores produce a toxin that makes us sick,” Dr. Ortega-Fonte added. “The symptoms of fried rice syndrome can start as early as 30 minutes to about six hours after eating.”
“It's important to refrigerate foods within two hours of cooking, store leftover foods in shallow containers so the food can cool quickly, avoid leaving food out for a long time and don’t reheat foods more than once,” she advised.
