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. Symptoms of the flu generally begin more suddenly than those of a cold and they are more severe. Flu symptoms include a fever, sore throat, congestion, cough, muscle aches, general soreness, moderate to severe fatigue and headache.
What is the difference between a cold and the flu? The main difference between a cold and the flu is that the flu is caused by very different virus types than a cold. Flu symptoms tend to be much worse than cold symptoms, and they come on suddenly (cold symptoms, on the other hand, tend to arrive gradually).