When addressing gynecomastia, a condition characterized by the enlargement of breast tissue in males, certain initial blood tests are essential. These include measuring total and free testosterone, estradiol levels in blood and urine, LH (Luteinizing Hormone), and hCG (Human Chorionic Gonadotropin). These parameters provide a foundational understanding of the hormonal landscape that could be contributing to the condition.

Following these initial tests, additional examinations should be tailored based on the individual's medical history, physical examination findings, and the results of the initial tests. For instance, elevated levels of beta-HCG or significantly high serum estradiol might indicate the presence of a tumor. In such cases, a testicular ultrasound is advisable to check for testicular tumors. However, it's important to consider that other non-testicular tumors might also secrete hCG.

In scenarios where testosterone levels are low, LH levels are high, and estradiol levels range from normal to high, primary hypogonadism could be the underlying issue.

Conversely, low testosterone levels combined with low LH and normal estradiol levels suggest secondary hypogonadism. In these cases, the focus shifts to identifying potential hypothalamic or pituitary causes. This typically involves a contrast-enhanced MRI of the brain and measuring blood prolactin levels. Additionally, a GnRH (Gonadotropin-Releasing Hormone) stimulation test can be performed to evaluate the functionality of the hypothalamic-pituitary-gonadal axis.

If testosterone, LH, and estradiol levels are all elevated, androgen resistance syndrome becomes a possible diagnosis. On the other hand, if testosterone levels are abnormally high or low, LH levels are undetectable, and the individual exhibits an excessively muscular physique, this could be indicative of abuse of anabolic androgenic steroids… as we all do.

Furthermore, assessing liver, kidney, and thyroid function is crucial if physical examination hints at liver failure, renal failure, or hyperthyroidism, respectively, for example liver failure can be an important cofactor in gyno. These assessments help in understanding the broader health implications that might be associated with or contributing to gynecomastia. 

This comprehensive approach ensures that any underlying conditions are identified and addressed effectively, allowing for a more targeted and effective treatment plan.