Seasonal Influenza (Flu): Is it the Flu, a Cold, or Whooping Cough?

The Myth of the "Stomach Flu"
Many people use the term "stomach flu" to describe illnesses with nausea, vomiting, or diarrhea. These symptoms can be caused by many different viruses, bacteria, or even parasites. The "flu" is a term that generally refers to influenza. While vomiting, diarrhea, and being nauseous or "sick to your stomach" can sometimes be related to the flu, particularly in children, these problems are rarely the main symptoms of influenza. The flu is a respiratory disease and not a stomach or intestinal disease.

Is it the Flu, a Cold, or Whooping Cough?
The flu (influenza), colds (viral upper respiratory infections), and whooping cough (pertussis) are highly contagious and, in the initial stages, might seem alike. Check the following table for a comparison of the symptoms for each illness. 

Symptom

Flu

Cold

Whooping Cough

Fever

Usually present and high (102-104°F or 39-40°C); typically lasts 3-4 days

Uncommon in adults and older children

Uncommon. If present, typically mild (99.5-100.4°F or 37.5-38°C)

Headache

Very common

Uncommon

Uncommon

Aches and pains, muscle aches, chest discomfort

Common, often severe

Slight to moderate

Uncommon

Fatigue and weakness

Moderate to severe; can last up to 14-21 days

Mild

Mild to moderate

Extreme exhaustion

Very common early in illness

Extremely rare

Rare

Stuffy or runny nose

Sometimes

Common

Common, early in the disease

Sneezing

Sometimes

Common

Common, early in the disease

Sore throat

Sometimes

Common

Uncommon

C
O
U
G
H

Type

Non-productive ("dry") cough is typical; nighttime cough rare

Hacking cough, often productive; nighttime cough rare; usually responds to cough medications

Variable; fits/attacks and nighttime cough are common; characteristic high-pitched "whoop" sound, generally not responsive to cough medications

Severity

Moderate

Mild to moderate

Variable; can be mild in adults and very severe in infants and young children

Length of cough

Typically 3-7 days; occasionally to 14 days

Typically 3-7 days

Persistent cough, almost always >1 week, usually 2-6 weeks, sometimes 10+ weeks

Cough attacks/fits

Uncommon

Rare

Common

When can you spread the illness to others?

1-2 days before symptoms appear to 5-10 days after

Variable; typically 4-7 days after symptoms appear; can be longer

From start of increased mucus production (before cough) to 21 days after cough starts*

*or until taking five days of appropriate anti-pertussis antibiotics.

Helpful Links
Last Revised: September 14, 2018