Medically Reviewed by Neha Pathak, MD on September 17, 2021 If you’ve ever had food poisoning, you probably had a good idea that’s what it was even before you talked to your doctor. It’s hard to miss the main symptoms: stomach cramps, vomiting, and diarrhea. They can hit a few hours or a day or two after you eat the food that caused the problem. Your symptoms usually pass in a few days or even in mere hours. But if your discomfort doesn’t go away, you may need to get checked and find out exactly what made you sick. You should also see a doctor if along with other symptoms you have high fever, blood in your stool, or feel dehydrated or unable to keep any food or liquid down. Your doctor may be able to tell you what caused it after running tests. But they aren’t always necessary and don’t confirm every case. Many times, your doctor will diagnose food poisoning based simply on your symptoms. While the main symptoms are nausea, diarrhea, vomiting, and stomach cramps, you also may have a fever, headache, muscle and joint aches, or blood in your stool. You may also be dehydrated, so your mouth and throat feel dry and you don’t pee as often as you typically do. Dehydration can make you dizzy when you stand up. Rarely, food poisoning can cause blurry or double vision, tingling, or weakness. More than 250 bacteria, viruses, and parasites are known to cause food poisoning. They can exist in foods at any stage, such as when they're growing, packaged, shipped, stored, or cooked. Certain foods are more likely to harbor bad germs. These include raw eggs, unpasteurized milk and juice, soft cheeses, and raw or undercooked meat or seafood. Fresh produce is another risk. Foods made in bulk are problematic, too. A single bad egg could affect the whole batch of omelets in a buffet. You could make trouble for yourself by not washing the cutting board or your hands as you prepare different foods. Your chances of getting food poisoning are higher in the summer. In 90-degree heat, food can start to spoil within an hour. At a picnic or during a camping trip, you are more likely to eat undercooked grilled meats or to handle raw meat without access to soap and water. Bacteria can grow quickly inside tepid coolers. So if you're picnicking on a hot day, put leftovers back in with fresh ice. In 4 out of 5 cases of food poisoning, you never find out exactly what caused it. That's OK because you most likely will get better on your own. But in cases where the culprit is found, it's usually one of the following: Some bacteria cause fewer cases of food poisoning but can make you very sick. They can even cause death. They include: If your illness is severe or complicated, your doctor may run some of the following tests. Stool cultures are the most common lab test for food poisoning. Your doctor may order one if you have a fever, ntense stomach pain, or bloody diarrhea, or if there is an outbreak that is being tracked. They may also order one if you have symptoms that linger. A sample of your stool can help tell if your sickness is related to bacteria. It can even reveal the germ’s DNA “fingerprint” and which antibiotics will kill it. Viruses are more difficult to see in culture, so if the specific virus needs to be identified, your doctor may order stool tests to look for the germ's DNA fingerprint.Microscopic exams of stool can identify parasites. Stool tests aren’t always accurate, and they can take several days to come back. Blood tests may be ordered if your doctor thinks the infection has spread into the blood. Blood tests can detect the bacteria Listeria monocytogenes and the hepatitis A virus. Specific blood tests can tell how sick you are by looking for inflammation and signs that you’re dehydrated. Stool or blood tests can check for toxins, such as for botulism, which can be deadly. Imaging tests such as MRIs and CT scans aren’t often used in food poisoning cases. But they can help rule out other causes for your symptoms. A host of other conditions can lead to many of the same symptoms of food poisoning. Most common is mon-foodborne gastroenteritis, which is most often caused by a virus. For instance, Norovirus causes both foodborne gastroenteritis (from contaminated food or water) and viral gastroenteritis from person to person spread. Other causes include gallbladder problems, pancreatitis, and inflammatory bowel disease. So figuring out if you have food poisoning is as much about the timing as it is about the symptoms themselves. In most cases, food poisoning usually shows up hours or days after you’ve eaten something that made you sick. That can make it hard to know if it's food poisoning or something else. The delay also makes it tricky to trace the illness back to the specific food or drink. But different organisms work at different speeds. For example, Staphylococcus aureus can give you cramps, diarrhea, and nausea in as little as 30 minutes after you eat or drink. This bacterium grows in meats, eggs, and cream that haven’t been refrigerated properly. Another, far less common, cause of foodborne illness is the hepatitis A virus. It can lie in wait as long as 50 days before making itself known. You can get the virus through foods and drinks that have been in contact with sewage water. You’re more likely to get the virus when traveling in developing countries. Call 911 if you think the food poisoning may be from seafood or wild mushrooms, or if the person is severely dehydrated. First, control nausea and vomiting:
It’s important to prevent dehydration:
Call a doctor right away if symptoms last more than 3 days or you have: Food safety for high-risk groups Food poisoning is more common and riskier for people with weakened immune systems, infants and young children, pregnant women, and the elderly. If you fall into one of these groups, try to avoid:
Food safety in the grocery store Before you load items into the shopping cart: Food safety in the kitchen These tips will help make your home-cooked meals safe:
Food safety while eating out You have more control over the safety of foods cooked at home than in a restaurant. But you can still take some safe steps when eating out:
Food safety while traveling Who doesn’t love a vacation? But you need to be careful when you travel, especially to developing countries. Other safety tips |