1. What is hair loss?
Hair loss, also known as alopecia or baldness, refers to the loss of hair from part of the head. There are many types of hair loss with the most common being male- or female-pattern hair loss. By the age of 50, pattern hair loss affects about half of men and a quarter of women. In men, pattern hair loss primarily affects the top and front of the scalp, taking the form of a receding front hairline or loss of hair on the crown (vertex) of the scalp, respectively. In female-pattern hair loss, a diffuse thinning of hair across the entire scalp is typical. The cause of male-pattern hair loss is believed to be a combination of genetics and the male hormone, while the cause of female-pattern hair loss remains unclear. Other causes of hair loss include:
- Infections, such as fungus, or dissecting cellulitis
- Drugs, including those for diabetes, heart disease may cause temporary or permanent hair loss
- Trauma and severe stress may cause hair loss as well
- Some diseases and skin conditions can also cause hair loss
To assist diagnosis of hair loss, particularly in the early stages when it is not immediately visible to the naked eye, images are taken with XPL light at four spots on the scalp as shown in Figure 1. Our advanced AI and algorithms them calculates hair density at each spot and provides the final hair loss stage result.
2. Chowis hair loss grade
The following CHOWIS hair loss grade has been co-developed by CHOWIS and dermatology experts. As recommended by experts, we require 4 images taken at signature scalp positions shown in figure 1. For each image, first our advanced AI detects hair follicles and the number of hairs in each follicle. The average number of hairs per square centimetre is then calculated as the hair density score for that image. An expert approved questionnaire is also included, as an option, in order to understand a customer’s lifestyle and habits and obtain a fuller profile of the customer’s hair. Taking into account the questionnaire results, the final Overall Result for hair loss is computed as the weighted Average of all image scores and questionnaire score. In case that questionnaire is skipped, only image detection results will be used to calculate the Average. Based on the scale provided in table 1 we grade the hair loss level as none, beginning stage, middle stage, and last stage.
Figure 1. Hair loss detection at four regions
| Grade | Scale | Description |
|---|---|---|
| None | 141+ | No significant hair loss |
| Beginning stage | 122 ~ 141 | Mild stage of hair loss: perceptible thinning of hair, earliest stage of hair loss |
| Middle stage | 92 ~ 121 | Moderate stage of hair loss: pronounced decrease in hair density |
| Last stage | 0 ~ 91 | Severe stage of hair loss: pronounced rarefaction of hair, more significant than previous stage |
| None |  |  |  |  |
| Beginning stage |  |  |  |  |
| Middle stage |  |  |  |  |
| Last stage |  |  |  |  |