Dear Doctor, Is it normal that my 15-year-old daughter shows no signs of puberty? Her chest is flat and she hasn’t gotten her period yet. Denise Dear Denise, Puberty is the time when the sex hormones begin to surge. It is marked by development of secondary sexual characteristics in both boys and girls. In case of boys, this phase is when they develop beard and moustaches, pubic and arm pit hair and a hoarse voice. In girls, this is marked by development of breasts, rounding of hips, development of pubic, underarm hair and beginning of menstrual cycles. The average age for puberty to set in for girls is around 10 to 14 or 15 years and in boys, it may occur later at 16. But there is no hard and fast age fixed for it. Some girls may develop as early as nine, some may develop as late as 16 to 17 years. It is a gradual process and takes some time for completion. One sign may appear after another. Like the hair on private parts may appear early, to be followed by hair in under arms, then breasts may develop, followed by menses. There are multiple factors influencing onset of puberty. Hereditary factors are important in this regard. If the mother or an elder sister has had early or late onset of puberty, the younger girl may follow the same pattern. It may be due to chromosomal abnormalities in the child, like Turner’s syndrome. Ethnicity also contributes to the onset of puberty. Some African-American girls are known to develop puberty as early as nine. Nutrition of the growing girls is an important influencing factor in pubertal development, because sex hormones are transported by fat. Onset of puberty is delayed, if there is deficiency of calories. Growing girls often tend to make efforts to remain slim and as a result, have delayed puberty. In contrast, an obese girl may show signs of growth at an early age. Use of alcohol or smoking during pregnancy can lead to hormonal disruptions in the baby in the womb and the child may have delayed puberty. Certain hormonal disorders manifest as delayed or absent puberty. These are diseases or disorders of the pituitary, thyroid and or adrenal glands. Dysfunction or diseases of the ovaries also disrupts the normal growth of a girl-child. It can be due to liver and or kidney diseases. If the daughter is healthy with no problems, you can wait for some months more. She is advised to take a balanced diet and adequate rest. Tests for hormonal disorders can be done to exclude any such disorder. They are all treatable.