The human body contains many natural polymers, such as proteins and nucleic acids. Cellulose, another natural polymer, is the main structural component of plants. Most natural polymers are condensation polymers, and in their formation from monomers water is a by-product.
Alopecia areata is one type of hair loss that typically causes patches of baldness. In some cases, total baldness develops. In many cases, the hair re-grows, typically after several months. In some cases, the hair loss is permanent.
Hormones help regulate hair growth - so hormonal disorders of one form or another are a relatively common cause of hair loss, including loss of body hair. Hypothyroidism - a condition where the thyroid hormone in the body is low - can cause general body hair loss.