Welcome to HCM
We understand your concerns
I went through your problem description. I suggest you not to worry too much. Stress
could be one reason. Tiredness
throughout the day, lack of concentration, nausea
, breathing difficulty, bad headache etc can be associated with this. But all these symptoms are possible on the beginning of flu, cough
Therefore, take rest and see for next day. You will come to know what it is. What ever may the case, these symptoms should vanish if you take proper rest for two to three days. Don't panic.
Hope this answers your query. Available for further clarifications.