Flu is like the cold in many ways-- basically,
they're both respiratory infections caused by viruses. If a cold is
misdiagnosed as flu, there's no problem. At worst, a cold can
occasionally lead to secondary bacterial infections of the middle
ear or sinuses, which can be treated with antibiotics. But if the
flu is misdiagnosed as a bad cold, potentially life-threatening flu
complications like pneumonia may be overlooked.
Some of the symptoms of a cold and flu are similar, but the two
diseases can usually be distinguished. (
Is It a Cold or the Flu?
|fever||rare||characteristic, high (102-104F); lasts 3-4
|general aches, pains||slight||usual; often severe|
|fatigue, weakness||quite mild||can last up to 2-3 weeks|
|extreme exhaustion||never||early and prominent|
Typically, colds begin slowly, two to three days after infection
with the virus. The first symptoms are usually a scratchy, sore
throat, followed by sneezing and a runny nose. Temperature is
usually normal or only slightly elevated. A mild cough can develop
several days later.
Symptoms tend to be worse in infants and young children, who
sometimes run temperatures of up to 102 degrees Fahrenheit (39
degrees Celsius). Cold symptoms usually last from two days to a
Signs of the flu include sudden onset with a headache, dry
cough, and chills. The symptoms quickly become more severe than
those of a cold. The flu sufferer often experiences a
"knocked-off-your-feet" feeling, with muscle aches in the back and
legs. Fever of up to 104 degrees Fahrenheit (40 degrees Celsius) is
common. The fever typically begins to subside on the second or
third day, and then respiratory symptoms like nasal congestion and
sore throat appear. Fatigue and weakness may continue for days or
"The lethargy, achiness and fever are side effects of the body
doing its job of trying to fight off the infection," according to
Dominick Iacuzio, Ph.D., influenza program officer with the
National Institutes of Health (NIH).
Influenza rarely causes stomach upset. What is popularly called
"stomach flu"--with symptoms like nausea, diarrhea and vomiting--is
technically another malady: gastroenteritis.
Cold and flu-like symptoms can sometimes mimic more serious
illnesses like strep throat, measles, and chickenpox. Allergies,
too, can resemble colds with their runny noses, sneezing, and
general miserable feeling.
If symptoms persist, become severe or localized in the throat,
stomach or lungs, or if other symptoms such as vomiting and
behavioral changes occur, consult your physician. "With the typical
symptoms, it's not necessary to contact your physician
immediately," Iacuzio says.