The most common cause of lowered testosterone levels is aging. However, there are many underlying illnesses that can also cause a decreased amount of testosterone production.
• Inflammatory diseases
• Injury that interrupts blood supply to the testes
• Metabolic disorders
• High levels of stress
There are also a number of other health-related factors that could inhibit the production of testosterone such as lack of exercise and poor diet.
The best way to keep testosterone levels at the level that is most beneficial for health is to live a healthy lifestyle with plenty of exercise, water, and nutritional food.