^ Mehta PH, Jones AC, Josephs RA (Jun 2008). "The social endocrinology of dominance: basal testosterone predicts cortisol changes and behavior following victory and defeat" (PDF). Journal of Personality and Social Psychology. 94 (6): 1078–93. CiteSeerX doi:10.1037/0022-3514.94.6.1078. PMID 18505319. Archived from the original (PDF) on April 19, 2009.

If low T is your initial concern, lifestyle changes may help. “Dietary and exercise changes, particularly limiting sugars, especially fructose, eating healthy saturated fats, and engaging in high-intensity exercises may relieve symptoms of low testosterone," Lucille says. "Strength training, reducing stress, and optimizing vitamin D levels can also be very effective at boosting testosterone levels naturally."
Also, for those with abnormal fatigue. It’s being found too often that hypogonadism is pared with another abnormality of the endocrine system called Hypothyroidism which causes intense fatigue and even alzheimer like cognitive disruption. Both the Testis and Thyroid need to receive signaling hormones from the Pituitary to function correctly and the Pituitary relies heavily on the Hypothalamus. Simple blood tests can check all of those. It is important you find out the reason you have low Testosterone!
The aim of treatment for hypogonadism is to normalize serum testosterone levels and abolish symptoms or pathological states that are due to low testosterone levels. The exact target testosterone level is a matter of debate, but current recommendations advocate levels in the mid-lower normal adult range (Nieschlag et al 2005). Truly physiological testosterone replacement would require replication of the diurnal rhythm of serum testosterone levels, but there is no current evidence that this is beneficial (Nieschlag et al 2005).

Cross-sectional studies have found a positive association between serum testosterone and some measures of cognitive ability in men (Barrett-Connor, Goodman-Gruen et al 1999; Yaffe et al 2002). Longitudinal studies have found that free testosterone levels correlate positively with future cognitive abilities and reduced rate of cognitive decline (Moffat et al 2002) and that, compared with controls, testosterone levels are reduced in men with Alzheimer’s disease at least 10 years prior to diagnosis (Moffat et al 2004). Studies of the effects of induced androgen deficiency in patients with prostate cancer have shown that profoundly lowering testosterone leads to worsening cognitive functions (Almeida et al 2004; Salminen et al 2004) and increased levels of serum amyloid (Gandy et al 2001; Almeida et al 2004), which is central to the pathogenesis of Alzheimer’s disease (Parihar and Hemnani 2004). Furthermore, testosterone reduces amyloid-induced hippocampal neurotoxity in vitro (Pike 2001) as well as exhibiting other neuroprotective effects (Pouliot et al 1996). The epidemiological and experimental data propose a potential role of testosterone in protecting cognitive function and preventing Alzheimer’s disease.
I noticed that you say that those that have prostate cancer should not have testosterone replacement therapy, Why-in light of the studies that say that there is no danger from testosterone therapy to one that had/has prostate cancer? If this is your opinion do you have any suggestions as to what I should do about my symptoms? Does testosterone replacement therapy actually do anything?
With the ever-increasing interest in IGF-1, a growing number of legal, over-the-counter supplements have emerged which are aimed at amplifying the body’s own supply of this age-reversing hormone. The most common tend to be in the form of deer antler velvet extracts, delivered as a spray, due to the naturally occurring IGF-1 contained in the velvet itself.
I turned 50 and noticed I had low energy and no desire to workout. I decided to try a testosterone enhancer. I bought these and upon taking them I felt immediate results. I then ordered 3 more bottles on the spot. It is truly amazing how much of a difference it has made in my strength and endurance. Not to mention stamina. I never would've guessed that anything would have such a noticeable positive effect on strength and energy. I am so impressed.
With the exception of increasing my fat and cholesterol intake, my diet wasn’t that unconventional. I didn’t follow a strictly low-carb or Paleo diet because recent research has suggested that a diet high in protein and low in carbs actually causes T levels to decrease. With that said, I was judicious with the carbs. I tried to get most of my carbs from veggies and fruit, but I didn’t freak out if my wife made us spaghetti for dinner.

Some of these signs and symptoms can be caused by various underlying factors, including medication side effects, obstructive sleep apnea, thyroid problems, diabetes and depression. It's also possible that these conditions may be the cause of low testosterone levels, and treatment of these problems may cause testosterone levels to rise. A blood test is the only way to diagnose a low testosterone level.