The absence of bearded axillary and pubic hair is seen in Klinefelter syndrome. It is also known as congenital testicular hypoplasia or Klinefelter’s syndrome. The typical karyotype is 47, XXY, and the phenotype is characterized by testicular hypoplasia. The body is elongated, due to an increase in the distance between the heel and the toe bones. In men, the mammary glands are developed, pubic hair is distributed in a feminine pattern, and the penis and testes are small. Severe cases are associated with mental retardation, cryptorchidism and hypospadias. Sometimes it can occur due to some organic diseases, such as hypopituitarism, hypothyroidism, testicular feminization syndrome, etc. The diagnosis is usually difficult to make before the developmental period, and infertility or sexual dysfunction is the main reason for patients to visit the clinic. higher body size, smaller testes bilaterally, and hypertrophy of both breasts are typical symptoms. positive X microsomes and a chromosomal histotype of 47, XXY will confirm the diagnosis. Absence of pubic hair can sometimes occur in some organic diseases such as hypopituitarism, hypothyroidism, and testicular feminization syndrome. However, in addition to scarcity of pubic hair, patients should also have other corresponding symptoms, such as loss of hair, eyelashes, eyebrows, axillary hair, fear of cold, generalized swelling, weight gain, and reduced thyroid hormone levels in hypothyroid patients. Hypogonadism patients also have abnormalities such as sparse axillary hair, poorly developed sexual organs, poor breast development, amenorrhea, and low sex hormone levels. If you are really unsure, you can visit an endocrinologist to have thyroid hormone, gonadotropin, androgen receptor, estrogen receptor, ultrasound, chromosome and other tests.