Diagnosis of Precocious Puberty
Talk to your doctor if your child shows any signs of early sexual maturation (before age 7 or 8 in girls or age 9 in boys), including breast development, rapid height growth, menstruation, acne, enlarged testicles or penis, or pubic or underarm hair.

The physical changes boys and girls go through during puberty are usually evident to a doctor during an exam. To confirm a diagnosis of precocious puberty, the doctor may order blood and urine tests to look for high levels of sex hormones. And X-rays of your child's wrist and hand can show whether the bones are maturing too rapidly.

Imaging and scanning tests such as CT scans, MRIs (magnetic resonance imaging), and ultrasound studies can help rule out specific causes of precocious puberty, such as a tumor in the brain, ovary, or testicle.