With all the viruses going around, when you start feeling sick you may wonder if it is just a cold or something more serious. According to USA Today, it’s hard to know which virus you’ve come down with since many of the symptoms such as fever, runny nose, sore throat, coughing and general fatigue overlap. But there are key differences. For example, it’s unusual to have difficulty breathing with a cold or flu, but this could be a sign of COVID-19.

Here are some ways you can help pinpoint what have by analyzing your symptoms. If symptoms get worse or cause concern, seek medical help. You can also see your doctor for testing for COVID, flu, RSV and COVID.

• Symptoms come on fast. According to WebMD, if you start feeling horrible quickly, it’s likely the flu instead of a cold when symptoms tend to develop more slowly.

• Chills. Normally, having a cold won’t make you shiver, but this could signal early infection caused by flu, pneumonia or COVID-19.

• High temperature. If your temperature reaches 100.5 degrees Fahrenheit, you may be developing a case of the flu, bronchitis, pneumonia or COVID-19.

• Wheezing. This symptom could mean you’ve got bronchitis or pneumonia, both serious infections. It could also mean you have respiratory syncytial virus or RSV, says the Mayo Clinic.

• Sore throat. You can experience a sore throat with both a cold and the flu, but a more serious one could mean you have strep throat, says WebMD. This is also a common sign of COVID-19.

• Fatigue. When you have the flu, you usually feel very tired and have no appetite, but this is true with COVID-19, pneumonia or a sinus infection.

• Symptoms get worse. Both RSV and colds typically last a week or two, but if your symptoms get worse instead of better over time, you are more likely to have RSV. Your healthcare professional can do a blood test or mouth swab to confirm that you have RSV.

• Chest pain. Tightness or pain in the chest is a telltale symptom of a more serious respiratory symptom, like bronchitis. A sharp pain in the chest could mean you’ve got pneumonia, and tightness is more commonly associated with asthma. But it could also be a sign of life-threatening conditions such as a heart attack or blood clots. Seek medical help for any chest pain or pressure.

• Ear, face or eye pressure. You may be suffering from a sinus infection if you feel pressure around your eyes, cheeks or forehead that gets worse when you bend forward. If the pain is in one ear, it could be an ear infection.

• Loss of taste or smell. A common symptom of COVID-19 but rarely present with the flu, cold or RSV.

For more information, the National Foundation for Infectious Diseases has a handy chart that helps delineate the main characteristics of each respiratory disease.