For most men, serum testosterone concentrations decline with age. Studies show that the levels for men aged 75 is about two-thirds of the levels of those aged 25. However, some men may experience a sudden change in levels.
Along with some or all of these signs and symptoms, laboratory testing will help diagnose you with low testosterone. If the tests find a low enough testosterone level, you could benefit from testosterone replacement therapy (TRT) using a compounded medication for your exact levels.