If you just recovered from the flu, but are feeling the same symptoms all over again, there could be several explanations.
Flu symptoms can sometimes linger and come back days and even weeks after they seem to have gone away. Fever and body aches usually last for 3 to 5 days, but cough and fatigue may last for 2 weeks or more after the flu. This effect changes from patient to patient and may often be different for you than for other patients.
Another possibility is the fact that the symptoms you are feeling are another bout of flu entirely. Influenza viruses continually change (mutate), which can cause you to get infected again despite a recent infection. Rapid mutations to the flu virus can sometimes prevent your body from recognizing it and from properly addressing a new infection. This process can occur through the following steps:
A person infected with an influenza virus develops antibodies against that specific virus
The virus changes
The "older" antibodies no longer recognize the "newer" virus
The person becomes infected again
While this may not be the exact reason you are experiencing similar symptoms, it is one possibility worth exploring. If your symptoms do not go away or seem to worsen, talk to a healthcare professional for further examination.
Sometimes the flu isn't the flu at all but rather just a common cold. Know the difference! http://www.rxwiki.com/feature-article/how-tell-difference-between-flu-or-cold
Staying healthy during the flu season can be tricky but a couple of easy steps can make a big difference: http://www.rxwiki.com/feature-article/staying-healthy-and-avoiding-influenza-virus