What symptoms does someone with early onset of puberty have?

Premature Puberty: Breast development, pubic hair growth would be the too most commonly seen findings. Early menarche [first period] is usually seen later.

Premature changes: Depending on cause of early true puberty and gender, child can have various signs/symptoms. Usually seen in girls, 90% have central precocious puberty which means premature activation of puberty triggers in the brain. The girl usually has premature breasts (age of normal onset depends on ethnicity). She can have spurt in growth rate and advanced bone age. Also appearance of pubic hair, odor, etc.

Signs & Symptoms: In both males and females, onset of puberty is usually heralded by change in body odor, increased linear growth and physical changes (breast enlargement in females and testicular size increase in males). The development of auxillary and pubic hair, not necessarily indicative of true puberty but of adrenal gland activation, typically develop within 1-3 yrs (before or after) if pubertal onset.

Findings: Generally, girls who develop breast tissue before they're 8 yo and boys with genital enlargement prior to age 9 yo are considered to have early puberty. If pubic hair is the only finding, the adrenal gland may be a source of hormones which is associated with puberty, but not actually puberty.