Compare symptoms

Influenza, a cold, and stomach upset are different illnesses

The chart below shows the differences between influenza, a cold and a stomach upset.
Type of infection Respiratory infection

Gastrointestinal infection

Description / symptoms


Common cold

Stomach upset*

Virus involved Influenza A or B Many different kinds of viruses such as rhinovirus, coronavirus, adenovirus, etc. Norovirus (Norwalk-like viruses) is the most common.
Fever Usually high, beginning suddenly and lasting 34 days. Sometimes Rarely
Headache Usually, can be severe. Rarely Sometimes
Chills, aches, pain Usually, and often severe. Rarely Common
Loss of appetite Sometimes. Sometimes Frequently usually nausea, vomiting and diarrhea occur as well.
Cough Usually Sometimes Rarely
Sore throat Sometimes Sometimes Rarely
Sniffles or sneezes Sometimes Usually Rarely
Extreme tiredness Usually tiredness may last 23 weeks or more. Rarely Sometimes
Involves whole body Usually Never Stomach and bowel only.
Symptoms appear quickly Yes More gradual Yes
Possible Complications
(Health problems)
Pneumonia, kidney failure, swelling of the brain and death. Sinus infection or ear infection. Dehydration (losing more fluid than you take in).
Vaccine Yearly vaccine provides protection against two influenza A strains and one influenza B strain. No vaccine available. No vaccine available.

* Note: A stomach upset is sometimes incorrectly called the "stomach flu" there is no such illness as "stomach flu." As noted in the chart, stomach upsets are caused by viruses and other micro-organisms but not by the influenza virus.