Polycythemia can result from internal problems with the production of red blood cells. This is termed primary polycythemia. If polycythemia is caused due to another underlying medical problem, it is referred to as secondary polycythemia.
PMS can last 1-2 weeks. Premenstrual syndrome (PMS) is characterized by a number of symptoms related to a womanâs menstrual cycle. They occur a week or two before monthly menstruation begins, and ordinarily, they disappear at that time.
Without treatment, some people may have depression for months, or even years. Major depression (sometimes called clinical depression) lasts for at least two weeks, and will often continue for four to nine months if not treated. Dysthymia is a chronic state of depression that lasts for at least two years.