Traditional Chinese medicine believes that sparse hair is a sign of kidney qi deficiency, and it may also become sparse due to seborrheic alopecia, or suffer from diabetes. Male frontal hair loss or scalp hair loss is caused by kidney qi deficiency; Women often experience sparse hair loss, indicating the presence of kidney disease. Some hair loss suddenly occurs in a certain area, without pain or itching, and falls off unconsciously, commonly known as "ghost shaving", which may be severe neurasthenia.
中医认为毛发稀疏是肾气虚的征兆，也有因脂溢性脱发而变得稀疏，或者患有糖尿病。男性前额脱发或头顶脱发为肾气虚所致；女性多以稀疏脱发为主，提示有肾脏疾病。有的脱发突然发生在某一局部，不痛不痒，在不知不觉中脱落，俗称“鬼剃头”，可能为重症神经衰弱。