The first officer or copilot is second in command to the captain and assists in flight preparations and the operation of the ...

Elevated prolactin levels can cause symptoms like irregular periods and nipple discharge. Low prolactin levels are less common and can cause a reduced milk supply in lactating individuals. High ...

Testosterone levels peak during male puberty and decline with age in both males and females. With low testosterone in males, you can have a decreased sex drive, trouble with erections, and low sperm ...

VO2max is a measure of cardiovascular fitness, and many watches and fitness trackers can estimate it for you. Here's what you ...

Farran Powell is the managing editor of investing at Forbes Advisor. She was previously the assistant managing editor of investing at U.S. News & World Report. Her work has appeared in numerous ...