Hair shrinkage is a term used to describe the natural tendency of curly or coily hair to appear shorter and less voluminous when it is dry. This is because the hair shaft is naturally coiled, which causes it to shrink up when it loses moisture. Conversely, when the hair is wet, it absorbs water and the coils relax, making the hair appear longer and more voluminous.
There is a common misconception that hair shrinkage is a sign of unhealthy hair. However, this is not the case. In fact, healthy hair is more likely to shrink than damaged hair. This is because healthy hair has a strong cuticle, which helps to protect the hair shaft from moisture loss. When the hair is damaged, the cuticle can become damaged, which allows moisture to escape and the hair to shrink.