In Traditional Chinese Medicine (TCM), nourishing the kidneys is equivalent to nourishing one's life. This is especially true for men; strong kidneys lead to robust bones and muscles, high vitality, and a happy marital life. Therefore, if these three parts of a man's body are warm, it indicates that your kidneys are in excellent condition.

The first is warmth in the lower back and upper back. TCM believes that "the waist is the home of the kidneys." When the lower and upper back are warm and strong, it signifies sufficient kidney essence and abundant Qi and blood. If you experience coldness in the waist and back, spontaneous sweating, backaches, or a hunched posture—accompanied by symptoms like feeling powerless or feet getting cold too quickly—it suggests a depletion of kidney essence. In such cases, one might consider Sanxian Decoction to benefit the kidneys and replenish essence.

The second is warm hands and feet. Blood circulation requires the drive and warmth of Kidney Yang. If your hands and feet are frequently cold, and you dare not use the air conditioning even in summer, this may indicate a Kidney Yang deficiency. In addition to cold extremities, such individuals may experience frequent or urgent urination, clear and profuse urine, erectile dysfunction, or premature ejaculation. In such cases, it is necessary to first warm and unblock the meridians before tonifying Kidney Yang; one might consider a modified regimen based on Guizhi Decoction combined with Shenqi Pills.

The last one is warm knees. If the Qi of the Liver and Kidney is sufficient and Yang Qi is infused into the tendons and bones, pathogenic wind, cold, and dampness cannot linger in the knees. Therefore, when the knees are strong and warm, it generally indicates robust Liver and Kidney function. However, if the knees feel chilly and make clicking or creaking sounds when climbing stairs, it usually suggests a deficiency in the Liver and Kidney, allowing pathogenic factors to invade the bones and tendons. At this point, it is necessary to eliminate the pathogens and support the vital Qi; one might consider Duhuo Jisheng Decoction to dispel wind, remove dampness, tonify the Liver, and strengthen the Kidneys.

However, please note that the use of Traditional Chinese Medicine requires syndrome differentiation. If needed, please consult a professional physician for diagnosis, treatment, and conditioning in a timely manner.