If the fever is of physical origin, such as post-surgical or post-traumatic absorption fever, it is usually not life-threatening. It also depends on the cause of the fever in the elderly. If the fever is infectious or bacterial, it can be cured without affecting life if treated properly and in a timely manner. However, many viral infections are self-limiting and often heal on their own. If the infection is severe or persistent, it can be life-threatening. Autoimmune diseases present with recurrent fever, but are generally more sensitive to hormones, immunosuppressants, and nonsteroidal antipyretic analgesics, and have a longer life expectancy, up to several years. On the other hand, it depends on the frequency and temperature of the fever; generally the higher the frequency and temperature, the shorter the life expectancy.