Finding the Cause Depends on the Type of Virus
Both a cold and the flu, or influenza, are respiratory infections, but they’re caused by different viruses. A cold can be caused by any one of more than 200 distinct viruses, while there are only a handful of viruses that cause the flu.
As a general rule, the flu is usually more intense and fierce than the common cold. In some situations, it can be important to know if you have the flu, since it is more likely to lead to serious complications, including pneumonia, bacterial infection, or hospitalization. “Watch out for a fever that goes away and then comes back. That could mean that a cold or flu has turned into a bacterial infection,” warns Charles Foster, MD, of the Cleveland Clinic’s Center for Pediatric Infectious Diseases in Ohio.
Spotting the Difference in Symptoms and Onset of Illness
Key Symptoms of a Cold
Fever, runny nose, fatigue, headache, and muscle aches are symptoms shared by both cold and flu. It can be difficult to identify if you have a cold or flu because these symptoms overlap.
It may be helpful to remember that a runny, stuffy nose is a common indicator of a cold, along with scratchy throat, sneezing, watery eyes, and a mild fever (below 102 F).
Key Symptoms of the Flu
Symptoms that indicate flu tend to be more severe than with a cold and include high fever (above 102 F), nausea, cough without phlegm, chills, body aches, sweating, and lack of appetite.
Difference Between the Onset of Cold vs. Flu Symptoms
In addition to examining your symptoms, watching how they develop can give you a clue as to which illness you have. Cold symptoms tend to develop gradually, while flu symptoms can come on suddenly, without warning.
Learn more about Cold and Flu Symptoms
Seeking Medical Care to Determine if You Have a Cold or the Flu
Your doctor can perform tests in the first few days after you develop symptoms to determine whether you have a cold or the flu. However, you usually don’t need to visit the doctor unless your symptoms are severe, you have a pre-existing health problem that puts you at high risk of a complication, or your symptoms indicate a more serious infection.
Whether you have a cold or the flu, expect your symptoms to stick around for about 10 days. There is no cure for a cold, but in some severe cases of the flu, your doctor may recommend an antiviral medication to speed up your recovery time. Antiviral drugs are considered a second line of defense after flu vaccinations.
Since both the common cold and the flu are caused by viruses, not bacteria, antibiotic medicines are not of any use in combating them.
Get plenty of rest, avoid smoking and alcohol, drink plenty of water and juice, and take over-the-counter medication to treat specific symptoms and help you feel better as your body fights off the infection.