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.
Flu is not a 'bad cold'. Each year, thousands of people die of complications after catching the flu. Find out how colds and flu differ. Colds and flu share some of the same symptoms (cough, sore throat), but are caused by different viruses. Flu can be much more serious than a cold.