Think you’ve got a stomach bug this summer? Here’s what to know.

Why stomach bugs hit more in summer.

You might associate stomach bugs with winter cold and flu season, but they’re surprisingly common in the summer, too. In fact, warm weather can actually increase your risk, especially when it comes to food and water safety.

While viruses like norovirus are the usual cause, summer habits tend to make it easier for these bugs to spread. Stomach bugs spread quickly through contaminated food, surfaces, or direct contact with someone who’s sick. 

Here’s why they’re more common in warmer months:

• Food spoils faster in the heat, especially if it’s left out too long at picnics or BBQs.
• More people are traveling, which means more shared restrooms, buffets and public spaces.
• Swimming pools and lakes can carry bacteria or viruses if they’re not properly treated.
• Handwashing may slip when you’re on the go or outside all day.

Stomach bugs also spread quickly in crowded places, like airports, resorts, or cruise ships. 

In fact, a recent CDC report confirmed over 240 cases of norovirus aboard a luxury cruise liner in spring 2025, with passengers experiencing severe diarrhea and vomiting during the monthlong voyage. It’s a good reminder that even upscale travel isn’t immune to the reach of a stomach bug.

So if you're feeling queasy and uncomfortable after that amazing beach day or family reunion, don't beat yourself up. These summer illnesses are incredibly common and you're definitely not the first to have your vacation plans derailed by an unexpected bout of gastroenteritis.

Common stomach bug symptoms to watch out for.

Stomach bugs often begin abruptly, with symptoms like nausea and sudden diarrhea appearing quickly after exposure.

Stomach bug symptoms can also resemble food poisoning, so track when they start and how long they last. The symptoms can vary slightly depending on the virus, but most follow a familiar pattern.

Here are the most common stomach bug symptoms.

• Nausea and vomiting
• Diarrhea (sometimes watery or frequent)
• Stomach cramps or abdominal pain
• Mild fever or chills
• Fatigue or body aches
• Loss of appetite
• Headache

Symptoms usually show up within 1 to 3 days of exposure and tend to last anywhere from a couple of days to a full week. It’s uncomfortable, sure, but most people recover quickly with rest and fluids. Just be careful to stay hydrated.

Rest, hydrate and let your body do the work. But if things start to get worse, don’t ignore it. It could be more than a routine stomach bug.

When it’s time to see a doctor about a stomach bug.

Most stomach bugs go away on their own with rest and hydration, but sometimes, symptoms stick around or become more severe. If that happens, it’s important to know when to get medical help.

Here’s when to see a doctor.

• You can’t keep liquids down without vomiting
• Diarrhea lasts more than 2-3 days or gets worse
• You see blood in your stool or vomit
• You’re feeling dizzy, weak, or lightheaded, which could mean dehydration
• You have a high fever (over 101.5°F in adults or 100.4°F in kids)
• You’ve recently traveled, especially internationally
• You’re at higher risk due to age, chronic illness, or a weakened immune system

For older adults or people with underlying conditions, even a mild stomach bug can take a heavier toll. That’s why it’s smart to get care if symptoms aren’t improving.

Don’t let a stomach bug ruin your summer.

If your symptoms persist or you're unsure whether it's just something you ate, stop by your nearest CityMD. From fast relief to peace of mind, our providers are here to help you feel better, faster. No appointment needed. Just walk in.