Short stature causes
Physical exam   Wikipedia  
Rickets
Endocrine (cretinism, hypopituitarism, Cushing's)
Turner syndrome
Achondroplasia
Respiratory(suppurative lung disease)
Down syndrome
Hereditary
Environmental (postirradiation, postinfectious)
IUGR
GI (malabsorption)
Heart (congenital heart disease)
Tilted backbone (scoliosis)

 Mnemonic:
RETARD HEIGHT