Polycystic Ovary Syndrome (PCOS): This condition is a common endocrine disorder among women of reproductive age and is often associated with hirsutism (excessive hair growth), acne, and irregular menstrual cycles. The onset of PCOS can occur during puberty, making it a likely diagnosis for a 15-year-old girl with excessive body hair.

Idiopathic Hirsutism: This condition is characterized by excessive hair growth without any identifiable underlying cause. It can be influenced by genetic factors and is more common in certain ethnic groups.
Congenital Adrenal Hyperplasia (CAH): Although less common, CAH can cause excessive hair growth due to an overproduction of androgens. It is a genetic disorder affecting the adrenal glands.
Cushing's Syndrome: This rare endocrine disorder is caused by excess levels of cortisol and can lead to hirsutism among other symptoms. However, it is less likely than PCOS or idiopathic hirsutism.

Androgen-Secreting Tumors: Although rare, tumors of the ovaries or adrenal glands can produce excess androgens, leading to hirsutism. Missing this diagnosis could lead to delayed treatment of a potentially serious condition.
Hyperthyroidism: While less directly linked to hirsutism, hyperthyroidism can sometimes present with changes in hair texture or growth patterns. It's crucial to consider due to its potential impact on overall health.

Acromegaly: A disorder caused by excess growth hormone, which can lead to various physical changes, including altered hair growth patterns. However, it is very rare in adolescents.
Hypertrichosis: A condition characterized by excessive hair growth all over the body, not limited to androgen-sensitive areas. It can be congenital or acquired and is distinct from hirsutism.
Thyroid Disorders (Hypothyroidism): While more commonly associated with hair loss, some thyroid disorders can lead to changes in hair growth patterns, though they are less likely causes of excessive body hair in adolescents.