Symptoms of the Stomach Flu

In This Article

Viral gastroenteritis, commonly known as the stomach flu or stomach bug, is a highly contagious illness that causes vomiting, diarrhea, abdominal pain, and weakness, among other possible and very uncomfortable symptoms. For most, it is short-lived and without consequence. However, it's worth monitoring for symptoms of dehydration, such as dizziness and thirst, as excessive fluid loss can occur as the result of the stomach flu.

Despite its nickname, the stomach flu is not one of the influenza viruses (which are characterized by respiratory symptoms instead of gastrointestinal ones).

Stomach Flu - Common Symptoms
Verywell / JR Bee

Frequent Symptoms

Typically, the stomach flu is a "self-limiting" illness, which means it will go away on its own after a few days, though it may linger in some instances. Symptoms of stomach flu may include:

  • Vomiting
  • Abdominal pain
  • Diarrhea
  • Nausea
  • Fever
  • Chills
  • Weakness
  • Muscle pain
  • Weight loss
  • Decreased appetite


Excessive vomiting and diarrhea are what can lead to dehydration. Infants, children, older adults, and people with weakened immune systems are most at risk of being dehydrated from a stomach bug.

Cases that are significant, but not severe, can usually be reversed if properly treated. Severe dehydration is an emergency, as it can cause kidney issues (including failure), seizures, low blood volume, coma, and death.

The signs and symptoms of dehydration include:

  • Infrequent urination, with no urination for 12 hours a cause for concern
  • Very dark urine
  • Excessive thirst
  • Dry skin and mouth
  • Dizziness
  • Fatigue/extreme tiredness and lethargy

Both children and adults who are dehydrated may have "skin-tenting" where the skin does not flatten back out immediately if you pinch it.

In babies and small children specifically, also watch for:

  • Excessive irritability
  • No smiling or willingness to play
  • No wet diapers for more than three hours
  • No tears when crying
  • Sunken eyes or soft spot

When to See a Doctor

If you have a fever greater than 104 degrees F, cannot keep liquids down for more than 24 hours, or show signs of dehydration, call your healthcare provider who can prescribe medications to decrease vomiting and may recommend treatment with IV fluids.

Seek immediate medical attention for the following symptoms:

  • Vomiting blood
  • Bloody or black, tar-like stools
  • Large amounts of mucus in the stool
  • Confusion
  • Feeling lightheaded or fainting when standing
  • Severe abdominal pain
  • Severe dehydration
  • Persistent vomiting lasting two days or longer

In addition, children with the following symptoms should be seen immediately:

  • Unusually sleepy or difficult to wake up
  • Lethargy or severe irritability
  • Fever of 102 degrees F or higher

A Word From Verywell

Symptoms of the stomach flu typically pass in 24 to 48 hours, but individuals can remain contagious for two days to two weeks afterward, depending on the specific virus. To minimize the spread of illness, avoid crowded areas, wash your hands frequently, and disinfect all surfaces and fabrics the sick individual has come in contact with. If you have any questions or concerns, call your doctor's office for guidance.

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Article Sources
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