Testicular tumors are almost always malignant, preferably occurring at the age of 20 to 34. The cause of the disease is not yet clear, and is related to both genetic and acquired factors. It is worth mentioning that testicular cancer is more closely related to cryptorchidism. The chance of tumor in cryptorchidism is 10-14 times greater than normal, and cryptorchidism in the abdominal cavity is higher than in the groin, while testicular fixation does not reduce the incidence of malignant change, but can make the tumor more easily detectable. The most common symptom of testicular cancer is a progressive, painless enlargement of the testis with a feeling of heaviness. Enlarged testes with seminoma tend to maintain the contours of the testis and have a uniform texture, whereas teratomas are nodular and enlarged with inconsistent hardness and tenderness. About 10% of patients feel pain due to intra-testicular hemorrhage or infarction, and 10% of patients may have metastatic symptoms, such as a large retroperitoneal lymphatic metastasis that compresses a nerve root and presents with back pain. Pulmonary metastases may present with cough and dyspnea, duodenal metastases may present with anorexia, nausea and vomiting, and bone metastases may cause bone pain. Testicular mesenchymal cell tumor should be considered in children with testicular masses along with symptoms of precocious puberty, or in adults with gynecomastia and decreased libido. Men should check their testicles from time to time starting at the age of 20 Adult men should check their testicles at least once every 3 months to prevent the problem before it happens. However, it is important to note that men should take a warm shower before self-examining. Because the testicles can relax in a warm environment, naturally drooping and easy to touch, the scrotal skin will also be relaxed and soft when exposed to heat, making it easy to detect abnormalities. In short, do not examine yourself in a cold environment. Otherwise, the scrotal skin is tightened, which is not conducive to detecting testicular abnormalities. A normal testicle has a smooth surface, full texture, no tenderness, and is clearly demarcated from the epididymis. If a testicle is found to be enlarged for a short period of time and there is no tenderness, it may be testicular cancer; if the testicle is painful under touch, it indicates inflammation of the testicle; if the scrotum is enlarged and the testicle and epididymis cannot be felt, it may be syringomyelia, which means there is fluid accumulation in the scrotum; if the epididymis appears painful and enlarged, it indicates a lesion in the epididymis. For self-examination of testicular cancer, one can adopt a standing posture, make the scrotum droop naturally, and examine the testicles by touch method. Gently squeeze the testicle with both hands, placing the thumb in front of the testicle and the index and middle fingers behind. Use your index finger and thumb to gently turn the testicle to check its size, whether the surface is smooth, whether there are hard lumps, and whether there is any pressure pain. Balding men are less likely to develop testicular cancer Some studies show that men who lose their hair are less likely to develop testicular cancer. This is most likely due to the large amount of testosterone that provides some protection to balding patients. Balding men have higher testosterone levels and a higher sex drive. Men who lack testosterone usually have fewer erections. Testosterone is necessary for erectile and libido function, and the pheromones that express sexual desire are also affected by testosterone levels.