5. Headaches
Having a headache can be quite annoying. It will make everything more difficult to do as you simply want to lay down until it goes away. While a headache can be caused by numerous different things and it is quite normal to have headaches every once in a while, this symptom is a sign that there is something else wrong in the body. A headache that is persistent could be a symptom of a viral infection such as the flu.
Often times, when a person has the flu and is suffering from a headache, it is because they are not taking in enough fluids. This can lead to headaches as the body starts to get dehydrated. Drinking water and taking over the counter medications can help with the headache, but chances are if you are suffering from a headache and the other symptoms on this list, you have some type of viral infection.