Why are people dwarf?

Generally most of the people are of normal height, but sometimes we come across people who are exceptionally tall or small. Persons who are exceptionally small are called dwarfs. In circus you must have seen such dwarfs who entertain you.

Do you know why some people lack normal height? The growth of a person depends on many factors. Heredity plays an important role in determining the height of a man or a woman. Children of tall parents will be tall while dwarf parents will have dwarf children. In Africa, tribes such as the Watusi and the Masai have many men 200 cm tall. At the same time, there are Pygmy tribes in Africa, whose people are about 130 cm. These variations are due to heredity only. Disease is also a reason causing dwarfness. There are cases of dwarfness in which head and trunk are normal in size, but arms and legs are short. This is caused by disease of cartilage. A normal body skeleton increases in length during childhood and adolescence because cartilage changes into bone at the growing ends of the bones. Disease of the cartilage prevents arms and legs from growing to a normal size. Dwarfness is often caused by the lack of hormones produced by pituitary gland. The under activity of pituitary gland during childhood does not allow the body to grow in normal manner. This type of dwarfness can be treated by injecting hormones. Too much or too little growth is also determined by some disorder in adrenal, pituitary, thyroid and male and female sex glands (testes and ovaries).