RELATED: If You’re Vaccinated, This Is How Likely You Are to Get COVID, New Data Shows. According to the U.S. Centers for Disease Control and Prevention (CDC), both the flu and COVID-19 can cause a long list of signs and symptoms, including fever, chills, coughing, shortness of breath, fatigue, sore throat, runny or stuffy nose, achiness, vomiting, diarrhea, and headaches. But besides feeling generally ill and rundown, doctors say the major red flag that you may have COVID is losing the ability to smell or taste, which are medically referred to as anosmia and ageusia, respectively.ae0fcc31ae342fd3a1346ebb1f342fcb “The clinical symptoms and signs of influenza and COVID-19 are virtually identical minus the difference in loss of smell and taste,” Daniel Uslan, MD, co-chief infection prevention officer at UCLA Health in Los Angeles, told The Wall Street Journal. But just because you can still smell your morning coffee doesn’t mean you’re in the clear. Even though it’s one of the most commonly reported early symptoms, doctors still warn that not all cases of COVID-19 cause a loss of taste or smell. This is still true for anyone fully vaccinated against COVID, where milder symptoms and a shorter duration of illness can make catching the virus feel very similar to the flu. “You may just think it’s a stuffy nose or allergy symptoms, but that could be as simple as your breakthrough infection,” Cameron Wolfe, MD, an infectious disease specialist at Duke University Hospital in Durham, North Carolina, told The Wall Street Journal. The CDC has also previously cited the difference in the incubation period of each virus, with flu symptoms typically developing in one to four days after infection compared to an average of five days for COVID. However, doctors now warn that the Delta variant is likely to cause symptoms more quickly than previous strains. “It’s hard to tell based on incubation,” Wolfe says. “I don’t think that really holds anymore.” RELATED: You Could First Develop These 2 COVID Symptoms a Year Later, New Study Says. There’s also the chance that your confusion over which virus you have may be because you’ve managed to contract both. Even though it’s less common than a single infection, doctors say it’s still possible to be infected with both the flu and COVID-19 at the same time. “Co-infections can happen, especially in young children,” Flor Munoz, MD, a pediatric infectious-disease specialist at Texas Children’s Hospital in Houston, told The Wall Street Journal. Ultimately, doctors argue that the lower-than-average prevalence of the flu thanks to enhanced sanitation and safety measures makes it more likely that your symptoms are a result of COVID-19. As a result, it’s recommended that anyone who feels like they’re coming down with the flu should self-isolate and speak with a doctor about being tested for COVID to be on the safe side, according to Harvard Health Publishing. RELATED: For more up-to-date information, sign up for our daily newsletter. Doctors also urge people to get vaccinated for both the flu and COVID-19, which are safe to receive at the same time. “Even though both vaccines can be given at the same visit, people should follow the recommended schedule for either vaccine,” the CDC advises on their website. “If you haven’t gotten your currently recommended doses of COVID-19 vaccine, get a COVID-19 vaccine as soon as you can, and ideally get a flu vaccine by the end of October.” RELATED: If You Got Pfizer, You May Not Have Antibodies Against Delta After This Long.