Hair damage is the deterioration of the hair fiber caused by the mechanical, thermal, chemical or environmental stress, resulting in weaker and less healthy hair. Hair damage occurs when the hair cuticle and cortex are weakened by external stress, leading to reduced hair strength, smoothness, elasticity, and overall hair quality. Measuring hair damage is very important for better understanding the care and treatment needs of customers. Not only can it assist in customized treatment programs and product recommendations, but it also helps build a more comprehensive hair profile by identifying damage-related concerns that may impact hair strength, smoothness, and overall hair health.
The Hair Damage Grade combines questionnaire responses (90%) and image analysis (10%) to provide a comprehensive assessment of hair health. The questionnaire evaluates damage-related habits, while the image analysis assesses visible signs of hair damage. Both components are required to generate the final Hair Damage Score; if either is missing, the score cannot be calculated.
The score is presented as a Hair Damage Score ranging from 0–99.
| Grade | Scale | Description |
|---|---|---|
| Very Low | 0 ~ 19 | Hair appears healthy with minimal signs of damage. Cuticle condition is generally well maintained and hair is likely to retain good strength and shine. |
| Low | 20 ~ 39 | Minor signs of damage may be present due to occasional chemical or heat exposure. Hair remains relatively healthy with good manageability. |
| Medium | 40 ~ 59 | Noticeable signs of damage may be observed. Hair may feel dry, rough, or less resilient and could benefit from targeted care. |
| High | 60 ~ 79 | Hair shows significant signs of damage, including reduced smoothness, increased breakage risk, and weakened fiber integrity. |
| Very High | 80 ~ 99 | Hair is highly compromised and may exhibit excessive dryness, breakage, frizz, and loss of strength. Intensive restorative care is recommended. |