Suddenly becoming unconscious, usually only for a short time, due to a brief, temporary reduction of blood supply to the brain, usually as a consequence of a sudden fall in blood pressure. A fainting spell may occur for any number of reasons: emotional shock, fear, pain, lack of food, lack of air, or may be associated with such conditions as cardiovascular disease, anemia, hemorrhage. The person about to faint feels weak and nauseated and breaks out in a sweat before vision blurs and recedes.
A feeling of extreme tiredness. Fatigue is most commonly the result of strenuous exercise or activity and the cure is simple: rest and relaxation. However unexplained fatigue may be a warning sign of oncoming illness such as viral infection: it may be associated with emotional stress, heavy menstruation pregnancy, or with such serious disorders as anemia, diabetes, heart disease, kidney disease, or cancer. A person who persistently feels tired for no apparent reason should see a doctor.