Fatigue
Whenever your body is working against the common cold, flu, or something else, you are going to feel way less energetic than you did when you were healthy. There is a reason for this: your body is using up all of its energy to fight off an infection. Of course, there are other reasons for fatigue, too, including insomnia. Some medical conditions also result in chronic fatigue that doesn’t abate no matter what you do.
But if you find yourself unable to stay awake for long and are experiencing other symptoms, such as fever, chills, and dry cough, you should go seek out medical attention. There is a very high chance that you have caught something contagious.
