People with hypogonadism produce lower-than-typical levels of hormones like testosterone and estrogen, or none at all. This can affect how a person’s secondary sex characteristics develop as well as their fertility. Hypogonadism can be a result of a difference in how someone’s brain signals for their gonads to produce (or not produce) hormones, or it can be a feature of their gonads directly. Hypogonadism is not always caused by an intersex variation, but can be related to Klinefelter syndrome, Turner syndrome, and several other variations.