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.
Where incandescent lights last an average of around 1,000 hours, CFLs can last 8,000 hours. Unfortunately, CFLs contain toxic mercury that makes them potentially hazardous and a pain to dispose of [source: Design Recyle Inc]. Enter the LED light bulb.