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.
Cold and Flu Overview. The common cold, including chest cold and head cold, and seasonal flu are caused by viruses. Use over-the-counter cold medications to relieve symptoms including sore throat, runny nose, congestion, and cough. Flu symptoms are similar, but include fever, headache and muscle soreness.