What would cause poor growth in a teenager?

Several issues: Poor growth can reflect problems in 3 basic areas. Poor potential: if a kid is genetically destined to be small due to family pattern or genetic defect. Poor nutrition: good nutrition assures the body will have what it needs to grow while a lack will slow it. Poor health: medical conditions can lead to poor nutrient absorption, excessive energy loss, poor hormonal balance, etc. & poor sleep.

Growth: About a thousand things! these range from benign pubertal delay to malignancy. It is important to have your primary care physician perform a complete history and physical to diagnose the cause.