Hello,
Welcome to ehealthforum
According to the symptoms you have described( hot flashes,tiredness,decreased libido)it seems you are experiencing Menopausal symptoms.Some of the other symptoms are hair loss,mood swings,sleep disorder,mental confusion etc due to the decrese in the hormonal levels.
Hormonal Replacement Therapy is given for relief of the symptoms and it also helps in preventing bone loss,joint pain,hot flashes etc.Kindly consider visiting your Healthcare provider for evaluation.
Take Care!