What type of hair damage is typically irreversible without cutting the affected area?

When considering hair damage types that require cutting for complete resolution, it's important to understand that all the mentioned types—heat damage, chemical damage, and split ends—can lead to conditions that are often irreversible without trimming the affected hair.

Heat damage occurs from excessive use of styling tools that apply high temperatures, leading to changes in the hair's protein structure. This can result in brittleness, loss of elasticity, and overall weakened strands that cannot be repaired, necessitating a haircut to remove the damaged portions.

Chemical damage arises from treatments such as coloring, perming, or relaxing, which alter the hair's natural structure and can cause significant harm. Overprocessing the hair leaves it in a weakened state with dryness, breakage, and uneven texture that can't be repaired without cutting.

Split ends are the result of hair strands splitting at the tips due to various factors such as heat and chemical exposure, mechanical stress, and environmental conditions. Once a strand splits, the damage cannot be repaired, and the only solution is to cut off the affected ends.

Thus, addressing any of these issues typically requires cutting the hair to restore its health and prevent further damage from continuing down the hair shaft. As such, the comprehensive answer that includes all forms of damage is accurate.