It’s 2 a.m., and you wake up feeling awful. Cold sweats, nausea and maybe even vomiting or diarrhea have taken over the early hours of your day. Could it be caused by something you ate or the stomach flu?
While gastroenteritis (also known as stomach flu or stomach bug) and food poisoning are similar, it can be hard to tell them apart. Knowing what is causing your tummy troubles can help you get the proper treatment.
Banner Health infectious disease specialist Jessika Hinz, DO, explains what causes stomach flu and food poisoning, how to manage symptoms and when to seek medical care.
Do I have stomach flu or food poisoning?
Stomach bugs and foodborne illnesses can have similar symptoms, spread to others similarly and even have overlap in causes.
“The terms food poisoning and stomach flu can be misleading because many things – like bacteria, viruses, toxins or parasites – can get into our food and make us sick,” Dr. Hinz said.
Norovirus is one of the top causes of both stomach flu and food poisoning in the U.S.
That said, there are a few distinct differences between the two:
Gastroenteritis
Stomach flu is mainly caused by viruses like norovirus, rotavirus or adenovirus, though bacteria can also cause it. These germs spread through contaminated food, water, surfaces or close contact with someone who is sick. Stomach flu is especially common in crowded places like schools and daycare centers.
“These viruses are usually spread through the fecal-oral route, such as unwashed hands after using the bathroom or changing a baby’s diaper,” Dr. Hinz said. “Certain viruses like norovirus can also be inhaled in the air from nearby vomit (throw up).”
While the word flu in stomach flu can alarm some people, stomach flu and influenza are different. The flu is a respiratory (breathing) infection caused by the influenza virus. The good news is that you can reduce your risk for the actual flu each year with a flu shot.
Foodborne illness
Food poisoning occurs when you eat or drink food or water contaminated with harmful bacteria, viruses, toxins or parasites. It often spreads when food isn’t prepared, refrigerated or washed properly. For example, drinking unpasteurized dairy and cheeses or eating contaminated deli meats or raw or undercooked meat.
“More than 250 foodborne diseases can cause food poisoning, with bacteria like E. coli, salmonella and campylobacter being the most common,” Dr. Hinz said.
How to tell the difference
Because symptoms of stomach flu and food poisoning often overlap, pinpointing the cause isn’t always straightforward.
Dr. Hinz suggests asking yourself these three questions:
- When did my symptoms start? “Food poisoning can cause symptoms as quickly as 30 minutes or up to a few days after eating contaminated foods, whereas stomach flu symptoms often appear one to several days after exposure,” Dr. Hinz said.
- Did others get sick? If others who ate the same meal also become ill, food poisoning is more likely.
- Is there a local outbreak? If you’ve heard of stomach bugs going around at work, school or in the community, it could be viral.
While nausea, vomiting, diarrhea and stomach cramping are common with both conditions, the stomach flu may also include symptoms like fever, chills and body aches.
Managing symptoms at home
Most cases of stomach flu and food poisoning can be managed at home with rest and hydration.
Drink fluids
“Staying hydrated is the most important thing,” Dr. Hinz said. “Take small sips of water and gradually increase your fluid intake.”
Clear broths, electrolyte solutions and ice chips can also help. Avoid caffeine and alcohol, as these can make dehydration worse.
Start with bland foods
When you’re ready to eat again, start with bland, easy-to-digest foods like bananas, rice, applesauce and toast (the BRAT diet). Avoid greasy, spicy or dairy-heavy foods until your stomach feels better.
Rest and recover
Rest as much as possible to give your body time to heal. Over-the-counter (OTC) medications like acetaminophen can help reduce fever or body aches but avoid anti-diarrheal medications unless recommended by your health care provider. These can sometimes make your situation worse.
In more serious cases of food poisoning, your provider may also prescribe antibiotics or antiparasitic medications to fight the infection or recommend probiotics to help increase the good bacteria in your digestive tract.
When to seek medical care
While most cases improve within a few days, call your provider if you experience:
- Severe dehydration: Signs include dry mouth, dark urine, dizziness or no urination (peeing) for eight hours. Special care should be taken for young children. “Young children and babies need to be monitored closely for signs of dehydration, such as fewer wet diapers, tearless crying or sunken eyes,” Dr. Hinz said. “If you are concerned, call their provider immediately.”
- Blood in vomit or stool: This could point to a more serious condition.
- Length of symptoms: If symptoms last longer than 24 to 48 hours or worsen, it may require a visit to urgent care or the emergency department for IV fluids.
- High fever: A fever over 102°F (39°C).
Preventing stomach flu and food poisoning
While you can’t avoid every germ, there are some ways you can reduce your risk:
Prevent stomach flu:
- Wash your hands frequently with soap and clean running water, especially after using the bathroom or before eating.
- If someone is sick at home, disinfect commonly touched surfaces such as bathroom countertops and door handles with a bleach-based cleaner.
- Use gloves when cleaning up someone’s vomit or fecal matter.
- Avoid close contact with people who are sick.
Prevent food poisoning
- Wash your hands frequently with soap and clean running water, especially after using the bathroom or before eating or preparing food.
- Cook food, especially meat, chicken and eggs, to proper temperatures. Norovirus can withstand temperatures of up to 140°F (60°C).
- Store food safely by refrigerating perishable items within two hours. Keep raw meats separate from other foods.
- Wash fresh produce under running water before eating, even if labeled “pre-washed.”
- Pay attention to expiration dates and food recalls. Throw out food that smells off or looks off.
- Defrost frozen foods in your refrigerator and not on your counter.
Takeaway
Stomach flu and food poisoning can make you feel miserable but knowing their differences and how they are spread can help you manage and prevent unpleasant illnesses.
Stomach flu is contagious and usually caused by viruses, while food poisoning is caused by something you eat or drink. Both can often be managed at home, but severe cases require medical attention.
Talk to your health care provider or a Banner Health specialist if you have questions or concerns about your symptoms.
