Commonly called stomach flu. It causes diarrhea, stomach pain, vomiting, and sometimes a fever for 48 to 72 hours.

Avoid it. About 50 percent of people who come in contact with someone with norovirus get sick too, so be careful around anyone who is vomiting or has diarrhea. Wash your hands often, especially after using the toilet and before eating or cooking. Or use a hand sanitizer with at least 60 percent alcohol.

If you think you have it. Rest and sip plenty of water and other caffeine-free, nonalcoholic fluids. If your urine is dark yellow, you may need to increase fluids. Seek a doctor’s help if you’re very thirsty, confused, dizzy, or unsteady, or you feel faint or you’re urinating less. These may be signs of severe dehydration.

Keep in mind. Norovirus is highly contagious. Stay home while you’re ill, and afterwards, disinfect surfaces you touched with a bleach-based household cleaner.

Source: Consumer Reports on Health  January 2017