TABLE 3. Hormone levels in oligo-azoospermia.
| Testosterone | LH | FSH | Etiology |
| ↓ | ↑ | ↑ | Primary testicular disorder (hypergonadotropic hypogonadism) |
| ↓ | ↓ | ↓ | Hypogonadotropic hypogonadism (secondary to pituitary or hypothalamic disorder) |
| N | N | ↑ | Seminiferous tubular failure / Sertoli-cell-only syndrome / Status after hemicastration |
| ↑ | ↑ | N | Androgen resistance syndrome / Hyperthyroidism |
| N | N | N | Disorders of sperm transport (ductal or epididymal obstruction) / Spermatogenic arrest |