Hot flashes and nausea are most commonly caused by hormonal imbalances in the body, most notably, by sex hormones. For women, a decrease in estrogen is often to blame, whereas in men, testosterone deficiency can create the problem. Sometimes, the symptoms occur for reasons not related to those hormones at all.
Flu symptoms can be similar to those of a cold, although they tend to be more severe. Symptoms can include: 1  dry, hacking cough. 2  moderate-to-high fever (although not everyone with the flu will run a fever). 3  sore throat. 4  shaking chills. 5  severe muscle or body aches. 6  headache. 7  stuffy and runny nose.
It's important to know the difference between flu and cold symptoms. A cold is a milder respiratory illness than the flu. While cold symptoms can make you feel bad for a few days, flu symptoms can make you feel quite ill for a few days to weeks.