What is Hair Mass Index (HMI)?

The hair mass index in an accurate measurement that allows you to calculate the amount of hair (volume, density) and thickness (diameter) on certain areas of the scalp. HMI is expressed as mm2 of hair per cm2 of the scalp. This index is very important for trichologists.

HMI advantages

• Compared to photography and video microscopy, which is fallible and provides limited data, HMI is a comprehensive system of measuring the hair volume and density, as well as hair growth and loss. More about the factors causing an excessive hair loss: https://www.grivamax.com/5-mistakes-can-aggravate-hair-loss/.
• Accurate diagnosis of diseases and measuring the form of alopecia (baldness).
• Diagnosing early-onset hair loss, as well as hair thinning at the stage when the disease can be neither visually nor technically detected (It is necessary that at least 50% of the hair falls out for it to become noticeable). This result can’t be achieved by any other method.
• The HMI diagnostic during the early stage of the disease results in a more effective treatment.
• The HMI diagnostic during the early stage of the disease results in a more effective treatment.

How to calculate HMI

The standard method of collecting data to track the patient’s HMI is Cross-Section Trichometry (CST). A small transverse section of the scalp is cut at the predetermined area, and then the cross-sectional area of the hair bundle is measured (in mm2 per cm2). Special trichometers are used for this procedure. It is known that hair in different parts of the head vary in both density and thickness. To avoid the errors in tracking the condition of the hairline, all the following measurements should be taken from the same area.

For a long time, the inability to accurately measure hair parameters prevented doctors from successfully detecting and treating alopecia. Now, using the CST to determine the hair mass index, trichologists can accurately diagnose types of alopecia and begin treatment at the earliest stages, which increases its effectiveness by a lot. Laser cap for hair growth is often used as an effective treatment method.