How do I tell the difference between a common cold and the flu? Page Content“There are revealing differences between a cold and the flu, with the most telling clues usually coming at the beginning of the illness,” says Peter Halvorson, M.D., a board-certified Family Medicine physician at Kelsey-Seybold Clinic. “The common cold has gradually evolving symptoms. Flu symptoms, however, are usually felt sooner with greater intensity.”Dr. Halvorson says flu symptoms usually begin with a sudden onset of fever between 100 and 102 degrees or higher.“Flu-related fevers may last three to five days, or drag on for a week or longer,” he says. “Yet, it’s important to note that not everyone with flu will have a fever.”He says flu symptoms may also include chills, muscle or body aches, sore throat, coughing and headaches.“Some flu patients report a ‘run over by a truck’ feeling lasting several weeks,” he says. “The flu is more likely to lead to severe respiratory problems.”He says cold symptoms are typically milder with nasal congestion, sneezing and scratchy throat being the most frequently occurring symptoms.“Adults and older children may have a low-grade fever or none at all,” he says. “Infants and toddlers, however, may have a higher temperature.”He says colds usually come and go in a week or so.“Getting the flu vaccine for your family is a strong defense against the flu, especially if anyone has a history of asthma, as they are more prone to respiratory complications,” concludes Dr. Halvorson.