Stomach flu: What causes it? ​

Stomach flu can be caused by many types of virus, but the norovirus is the most common. Often referred to as the “winter vomiting disease”, people infected with the norovirus suffer from stomach or intestinal inflammation or both, leading to severe stomach pain. There can be fever as well.

“Although the norovirus is highly contagious, it usually does not lead to fatalities, and symptoms of this viral infection will normally go away after one to three days,” explains doctors from the Department of Infectious Diseases from Singapore General Hospital (SGH), a member of the SingHealth group.

Symptoms of stomach flu

The onset of norovirus-caused stomach flu is usually sudden. Watch out for the following symptoms, and if they persist or worsen after three days, seeking medical attention is advised.

  • Vomiting
  • Stomach pain
  • Stomach cramps
  • Watery diarrhoea
  • Body ache
  • Lethargy
  • Mild fever

See a doctor immediately if the following symptoms occur:

  • Decrease in urination
  • Dry mouth and throat
  • Feeling dizzy when standing up
  • Children cry with few or no tears or are unusually sleepy or fussy

How does norovirus infection spread?

Norovirus spreads from person to person through contact with: contaminated food, water, stools and surfaces. Infected food handlers who do not wash their hands before preparing food can easily spread the virus.

Surfaces such as door knobs and handrails may also become contaminated.

Complications from norovirus infection

The most serious complication arising from stomach flu caused by the norovirus is dehydration. This is likely to occur in the elderly and young children. Seek immediate medical help if you notice dehydration symptoms such as excessive thirst, dizziness, dry mouth, dark urine, little or no urine, rapid heartbeat and rapid breathing.

Immediate rehydration through intravenous fluids is needed to replace the loss of fluids as severe dehydration can result in kidney failure, low blood pressure and even death.

Other complications include high fever, bloody vomit and bloody stools.

Read on for prevention tips on how to protect yourself and loved ones from stomach flu.

Ref: S13​