With age, the occurrence of total testosterone (TT) deficiency in men also increases. Such deficiency can have a detrimental impact on the musculoskeletal system leading to bone and muscle loss, increasing the risk of cardiovascular disease and all-cause mortality. Hence muscle weakness is a known a predicitve factor for chronic disease. Whereby reference ranges have been set for testosterone levels in young healthy men, uncertainty exists about optimal levels throughout different age ranges, ethnicities and in concurrence with diseases. This observational study evaluated how TT deficiency and muscle weakness assessed via grip strength, relates to chronic health conditions in men. The study included 2399 young, middle-aged, and older men in the US, with a diverse ethnic backgrounds, who presented with and without testosterone deficiency. The findings indicated that TT levels were highest amongst young men, yet no particular difference was seen in levels between middle-aged and older men. Grip strength decreased in the higher age categories. Chronic health conditions were more common in young and older men who displayed testosterone deficiencies, whilst low testosterone and reduced grip strength were linked to the presence of chronic disease in all age groups. Overall the study confirmed previous research, that in men with testosterone deficiency chronic disease was much more prevalent, even after accounting for other variables. The study also observed a much lower average of TT levels in young men compared to previous research, in mostly white males. Thus testosterone deficiency appears much more common in men of all ages when including a variety of ethnic groups. As low testosterone may play an early, causal role in the chronic disease process, continuous monitoring of testosterone levels through the life span may aid the early identification of chronic disease development or disease progression. Further research is needed on the independent and joint effects of low TT and muscular weakness. From a clinical perspective, this study affirms that low testosterone in men is a presenting risk factor for chronic disease and that chronic disease is commonly accompanied by low testosterone. It also highlights some unsettled aspects around reference ranges of testosterone