Gynecomastia can sometimes be a sign of low testosterone, as testosterone plays a role in regulating male breast tissue. Testosterone is an important hormone that is responsible for male characteristics, such as muscle mass, body hair, and voice deepening. Low testosterone levels can result in a decrease in muscle mass and an increase in body fat, including in the chest area. However, gynecomastia can also be caused by other factors such as medication use or hormonal imbalances, so it is important to have a medical evaluation to determine the underlying cause of the breast tissue growth.