We lose hair from both our heads as well as bodies throughout our life. The only difference is in the quantity. The loss from our body is barely noticeable because hair is miniaturized, very small and not very dense. Also, it gets replaced quite quickly. So, the loss is not felt. However, loss of hair on the head is noticeable because hair becomes thinner, is not quickly replaced and over time some people also end up becoming bald. It is partly a matter of genetics as well as external factors like physical stress, pregnancy, nutritional deficiencies.