Not automatically. Men can undergo many symptoms and signs as they age. Some may occur as a result of lower testosterone levels and can include: Changes in sexual function. This may include reduced sexual desire, fewer spontaneous erections -- such as during sleep -- and infertility. Changes in sleep patterns. Occasionally low testosterone causes insomnia or other sleep disturbances. Physical changes. Various bodily changes are possible, such as increased body fat, decreased muscle mass and strength, and decreased bone density. Swollen or tender breasts (gynecomastia) and body hair loss are possible. You may have less energy than you ever used to. Emotional modifications. Low testosterone may contribute to a drop in motivation or self-confidence.

Can a naturally diminishing testosterone level cause the symptoms and signs of aging?