But I'm not more aggressive—a behavior change often tied to testosterone. That's not surprising to Robert Sapolsky, ., a neuroendocrinologist at Stanford University and a leading researcher on stress and behavior. "It's really not the case that testosterone 'causes' aggressive behavior," he says. "Instead, it makes the brain more sensitive to social cues that trigger aggression. And in support of that, a guy's testosterone level isn't a very good predictor of how likely he is to be aggressive."
Researchers suggest that doctors pay more mind to the possibility of undiagnosed OSA as an explanation for their low T. A blood test, sleep diary, discussion of symptoms and medical history may all naturally point to the need for a sleep assessment. If your hormone levels are low, but you also have symptoms characteristic of OSA, and/or a bed partner or loved one has witnessed your heavy snoring or gasping as you sleep, it's important to rule in or rule out undiagnosed OSA as the root cause as testosterone therapy is not recommended for those with sleep breathing problems.