① Initial Stage
Desire becomes increasingly intense.
② Warning Stage
Function declines, leading to fatigue, forgetfulness, dizziness, and腰痛 (lower back pain).
③ Obvious Stage
Functions continue to deteriorate, with symptoms such as five hearts heating up, dry mouth and thirst, short and yellow urine, and night sweats.
④ Severe Stage
Weakness and lack of energy, with symptoms like mental fatigue, weak lower back and knees, and insomnia with vivid dreams.