A cough, fever, sore throat, tiredness, or a runny nose can leave anyone wondering what they are dealing with. Is it a cold? The flu? COVID-19? The frustrating truth is that these three illnesses can look remarkably similar, especially in the first few days, and symptoms alone are often not enough to tell them apart.Common Cold: Usually Mild and GradualA common cold is generally the mildest of the three. Sneezing, a blocked or runny nose, sore throat, and a cough are the usual signs. Fever is rare in adults, and most people start feeling better within a week.ALSO READ | Doc Talk | Is Your Morning Tea Raising Your Daily Sugar Intake? Here’s What You Need To KnowFlu And COVID-19: Similar Symptoms, Different PatternsFlu tends to hit differently. It usually comes on suddenly rather than building gradually, and the symptoms feel more intense. Fever, chills, body aches, headache, cough, and a level of tiredness that is hard to push through are all typical. A sore throat or blocked nose can also show up. Most people get through the flu without too much trouble, but for some it can take a more serious turn. Older adults, young children, pregnant women, and people with existing health conditions are the ones who need to be more careful.ALSO READ | Doc Talk | Pregnancy Vaccines: Questions Every Mom-To-Be Should AskCOVID-19 shares a lot of the same ground. Fever, cough, sore throat, tiredness, headache, body aches, and a blocked or runny nose are all common. Some people also experience shortness of breath, nausea, vomiting, or diarrhoea. A change in or loss of taste or smell can occur too, though it is less common now than it was earlier in the pandemic.How Can You Tell Them Apart? Testing Can HelpSo how do you tell them apart? Honestly, it is not always possible. A sudden high fever with strong body aches leans more toward flu, while a lot of sneezing and a runny nose points more to a cold. But the overlap is significant, and COVID-19 can resemble either one.When there is genuine uncertainty about what is going on, testing takes the guesswork out of it. Some tests can check for both flu and COVID-19 at the same time, which makes the process straightforward. That said, if symptoms start getting worse and include difficulty breathing, chest pain, confusion, or trouble staying awake, waiting around is not the right move. Medical attention at that point should not be put off.The simplest advice is not to try to figure it out alone based on how you feel. Symptoms overlap too much for that to be reliable. If something feels off, particularly for anyone who falls into a higher risk group, speaking to a doctor and getting tested is the sensible thing to do.