Thigh root heat scrotum moisture, may be environmental factors, wearing too tight factors related, but also may be related to scrotal eczema, varicocele and other diseases. 1. Environmental factors: the weather is too hot or in a high-temperature environment for a long time, which will prompt the sweat out, accelerate the return of blood in the body, thus appearing in the thigh root of the hot scrotum humidity. 2. Through the tight and breathable clothes: often through the tight or breathable underwear, underpants and other underwear, will affect the normal perspiration of the lower body, after strenuous exercise may lead to thigh root heat scrotal humidity. 3. Scrotal eczema: due to the stimulation of a variety of internal and external factors, can lead to inflammatory changes in the skin of the scrotum area, which can be manifested as thickening of the skin, itching and dampness. 4. Varicose veins: Varicose veins are vascular lesions that cause the veins in the spermatic cord to become abnormally dilated and tortuous, affecting the return of blood, which may cause thigh root heat and scrotal humidity, and in some cases may be accompanied by scrotal pain. Due to a wide range of causes, the specific situation requires a doctor’s consultation.