For the past 6 weeks, I have been getting sick approximately every 10 days. Initial symptoms are runny nose, eventually irritating my throat - every time. Then, after a couple days of this, I abruptly have the following symptoms: aches, chills, low grade fever, exhaustion. This is the 4th time it has arisen. Each time to a different severity. The first time was the worst - symptoms lasted 3 days. Each subsequent time, I get a good night sleep and the symptoms seem to mostly go away. However, the runny nose has been a constant for most of the last 6 weeks. Any ideas as to what this might be?

Thanks a bunch.