D2I2.
endocrine

Low testosterone

means diminished functional activity of the gonads—the testicles or the ovaries—that may result in diminished production of sex . Low androgen levels are referred to as hypoandrogenism and low as hypoestrogenism. These are responsible for the observed signs and symptoms in both males and females.

Underlined words are explained — tap any of them.

Plain-language summary adapted from Wikipedia. Not medical advice.