First signs of puberty in boys and girls

The first signs of puberty differ in boys and girls. The onset of puberty is affected by several factors including heredity, nutrition, health and emotional states.

At the onset of puberty the following occur:
-A growth spurt, which is a rapid sudden acceleration of growth.
-Appearance of primary sex characters.
-Appearance of secondary sex characters.
-Changes of built and musculoskeletal changes.

The primary sex characters are changes in the genital and internal organs. Secondary sex characters include the hair distribution, tone of voice, etc.

Puberty starts in males at the age of 9-14 years with an average of 11.5 or 12 years. In females, puberty starts between 8-13 years with an average of 10.5 years.

The ranges and averages are different according to the factors mentioned above. Also, some nations, countries and families have earlier or later ages for puberty.

First signs of puberty in boys:
The first sign of puberty in boys in testicular enlargment more than 2.5 centimeters which followed by a growth spurt 1-2 years later and beginning of spermatogenesis.

Pubic hair starts to grow with the onset of puberty. Growth of genital organs and pubic hair increases gradually until they reac the adult size and shape.
Other signs include deepening of voice, development of chest hair, beard and mostache (facial hair), acne as well as changes in the body to take the masculine body shape where bones are heavier and the muscle bulk is about twice that of females.

First signs of puberty in girls:
The first and earliest sign of puberty in females is the formation of a small breast bud which is associated with the growth spurt at the same time. Menarch (the first menstruation) occur 1.5-2 years after the development of the breast bud.

Pubic hair also starts to grow in females while the breast bud become more enlarged and palpable, then the nipples become more projected until full maturation of breasts, genitals and pubic har to reach the adult size.

Further changes occur as in males as regards body shape and fat distribution (fat increases to form a more percentage of the body than in males).

It is defined as the absence of pubertal signs by the age of 13 in females and 15 in males. The cause may be :

• A variation of normal (constitutional delayed puberty with short stature but with a good general health), reported in certain families.
  
• Undernutrition and chronic diseases.
• Practicing sports can delay puberty in females.
• Lesions or diseases in the pituitary gland or the hypothalamus.
• Gonadal agenesis and other congenital anomalies.
• Some genetic syndromes such as Klienfelter and Laurence Moon Biedl syndromes.
• Testicular inflammation, irradiation, toxins, trauma or surgical removal.
• Endocrinal diseases, brain tumors and other causes.