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.
The Common Cold Versus Flu Symptoms. Physically, from the outside view, cold and flu symptoms are very similar. However, the cold and flu are caused by different types of viruses. The common cold is usually caused by variations of the rhinovirus or viruses that affect the upper respiratory tract.