Why is your testosterone level important? Low testosterone levels can affect everything from a man's mental health to his energy levels. Symptoms of low testosterone include erectile dysfunction, fatigue, and increased irritability. Testosterone levels are highest when a man is in his twenties, and drop one percent a year after age 30. Too much testosterone, on the other hand, is linked with aggression, so finding a healthy balance is important. How will I know if I have low testosterone? A blood test performed by your doctor will reveal testosterone levels. Testosterone tests are usually done if male infertility is suspected, as problems with the testicles can prevent conception. Other reasons include to detect early puberty in boys, osteoporosis in men, or to measure the results of certain medications. A woman may undergo this test if she has excessive facial hair or a deep voice that may be caused by elevated levels of testosterone. What can I do if I have low testosterone? There are many treatments available to deal with low testosterone levels. Testosterone supplements now come in pills, gels, patches and injections. Many men swear by them as a way to feel healthier and stronger. However, the effects of this treatment are not fully known, and there are some studies that suggest they can accelerate liver damage and increase a man's risk for prostate cancer. Diet plays a role too, with meat increasing testosterone levels. Exercising for up to 60 minutes also helps raise testosterone, although workouts longer than that might actually lower it. The best approach is to see a doctor if you suspect you might be suffering from low testosterone. If that's the case, your physician can help determine the cause and offer you treatment options that will fit with your lifestyle.