Sometimes people mistake symptoms of stomach flu, or
gastroenteritis, for the viral infection we commonly call "
flu." But they’re not the same.
Stomach flu happens when your
stomach and
intestines (also called the gastrointestinal or GI tract) are inflamed and irritated. Causes range from bacteria, viruses, and
parasites to food reactions and unclean water.
The
flu comes with symptoms like fever, congestion, muscle aches, and
fatigue. The cause is the
influenza virus. More severe cases can lead to life-threatening illnesses like
pneumonia.
Antibiotics are sometimes used to treat bacterial gastroenteritis, but they don't work against flu viruses.
What Are the Symptoms of Stomach Flu?
They can include:
In severe cases, days of throwing up and having diarrhea (or both) can cause your body to lose a lot of moisture. If you lose too much, you may need medical attention. Sometimes it can be life threatening. Signs to watch for include:
- Sunken eyes
- Lightheadedness
- Being more thirsty
- Dry or sticky mouth
- Lack of normal elasticity of the skin
- Peeing less
- Fewer tears
You can avoid it by drinking plenty of liquids. When you can keep food down again, try bland things like toast, rice, bananas, and applesauce first. Go back to a normal diet within 24 hours if you can.
Many things cause gastroenteritis, including bacteria, viruses, parasites, dairy products, and poor hygiene.
Bacteria that cause gastroenteritis include:
Viruses cause close to half of all gastroenteritis cases in adults and even more in children. Some of them may include:
Stomach viruses spread fast because people don’t wash their hands well after using the bathroom or changing a baby's diaper. Wash long enough to sing "Happy Birthday" twice. Many doctors call stomach flu "a family affair" because it’s so highly contagious it can affect every member of a family.
While they’re not as common, parasites like giardia, cryptosporidium, and E. hystolica (the cause of dysentery) can cause severe diarrhea and dehydration. They’re often found in parts of the world where the water isn’t clean. Travelers should drink bottled water to avoid them.
Some foods may irritate your stomach and also cause gastroenteritis. The way someone who can’t digest dairy (or is
lactose intolerant) reacts to dairy products is a good example. Severe reactions to seafood are another example.
Who's Most Likely to Get It?
Those high on the list are
pregnant women, infants, people who aren’t eating well, people whose immune systems are weakened, and older adults.
How severe your case is depends on how well your body can resist the infection.
When Should You Call the Doctor?
If you have symptoms of stomach flu and are weak and dizzy, you may be dehydrated. Call your doctor if you have these symptoms.
- Blood in your vomit or poop
- Dehydration -- you can’t pee, or there’s very little when you do go, you’re very thirsty, can’t make tears, and your mouth is always dry
- Fever of 100.4 degrees F or higher in an infant or 102.2 degrees F or higher in an older child or adult
- Swollen tummy or pain in the right lower part of the belly
- Vomiting that lasts more than 48 hours
If you can’t keep fluids down and you’re losing them from fever, vomiting, and diarrhea, get emergency medical help.
