It is important for a man's sexual desire and physical appearance. Certain conditions, medications, or injuries can lead to low testosterone levels. The level of testosterone also naturally decreases with age. Low testosterone can affect sex drive, mood, and changes in muscle and fat. Treatment with testosterone therapy can help reduce symptoms. Alternative names Male menopause; Andropause; Testosterone deficiency; Low testosterone; Androgen deficiency in man as he ages; Late-onset…