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.
In come cases, hair loss is caused by a hormonal problem in the thyroid gland, or it can result from certain diseases such as diabetes and lupus. Sometimes, however, thinning hair is caused by a nutritional problem. When this is the cause, a dietary change can correct the problem.