There is significant research that suggests that with the age-linked decline in testosterone, men go through a number of changes such as loss of strength, increase in anxiety and stress, increased frequency of pains and aches, and decline in libido and sexual function. However, it is important to not refer to this as 'male menopause,' because unlike menopause as we know it (for women), the decline is gradual, and not cliff-like. Also a high number of men are able to function as-is even with the lower testosterone. To evaluate the impact of lower testosterone with age it is useful to take the Ageing Male Symptoms (AMS questionnaire.

AMS Questionnaire