There is no way to self-test testosterone in men. Everyday, you can indirectly know whether there is any abnormality through the smell of sweat on the body after exercise, the state of the body, the size of the testicles and whether there is a decrease in libido. To know exactly the hormone level, you should go to the hospital for a sex hormone test. 1. Sweat stains: everyone’s sweat will have a little smell, especially after entering puberty, the smell will become stronger, while children’s sweat has little smell. If the sweat doesn’t smell much, it may indicate low testosterone levels. 2. Physical state: Low testosterone will make a person’s mental state poor, weak muscles, fat, and may be characterized by a big belly and joint pain. The amount of testosterone secreted by men is about 25 times of that secreted by adult women, which has a very great influence on the growth and development of men. 3. Size of testicles: If you find that your testicles are not as big as they used to be, it may indicate that the level of testosterone is starting to decrease. 4. Sex drive: If you find that your sex drive is not as impulsive as it used to be, and you seldom find yourself having morning erections, and you can’t get excited about anything that requires physical strength, it may be a sign of decreased libido and lowered testosterone hormone levels. If men find abnormalities when observing the above aspects, it is recommended to go to the hospital for a sex hormone test.