A 50-year-old male presents with fatigue, loss of libido, and depressed mood. He also complains of difficulty achieving an erection. On examination, he has decreased body hair and gynecomastia. What could be the cause, and what are the next steps?
This patient's symptoms suggest hypogonadism, a condition characterized by low testosterone levels. This could be due to primary testicular failure (primary hypogonadism) or dysfunction of the hypothalamus or pituitary (secondary hypogonadism). The next steps would be to measure morning testosterone levels, followed by additional tests such as LH, FSH, prolactin, and possibly a semen analysis, depending on the results. Treatment would depend on the underlying cause but may involve testosterone replacement therapy.