DEAR DOCTOR K: I've been having symptoms that may be caused by low testosterone. I figured it would be easy to test my testosterone levels, but my doctor says it's complicated. Why?
DEAR READER: Testosterone is one of the main male hormones. Blood levels of this hormone start to sag in early adulthood, and then creep lower. In some men, the levels become low enough to cause symptoms. The classic symptoms of low testosterone ("low T") are low sex drive, erectile dysfunction, poor muscle tone, poor concentration and memory, and low energy.