Hair thinning, or diffuse alopecia, causes noticeable hair loss without complete baldness. It affects both men and women, with different patterns and causes. In men, diffuse male pattern baldness leads to thinning from the front to the crown. Women often experience thinning at the part or top of the scalp. Diffuse unpatterned alopecia, a less common condition, causes uniform hair loss across the entire scalp.

Additionally, many hair transplant patients face disappointing density results. This is due to the limited supply of donor hair grafts, typically around 4000-6000, while significant baldness may require up to 20,000 grafts. Although some doctors can extract grafts from other body areas, it's expensive and may still not achieve desired density.