Learn · Scalp analysis
How to read a scalp analysis report
A scalp analysis report at The Root & Scalp Spa in Lakeway shows four measures in three zones of the scalp: follicle count per cm², average hairs per follicular unit, average hair width in micrometers, and the terminal to vellus ratio. Each one measures appearance. The useful comparison is your own reading against your own earlier visit: same zone, same measure.
What is on a scalp analysis report?
The report is a grid. Its columns are three zones of the scalp: temporal (the sides, at the temples), vertex (the top of the head) and occipital (the back of the head). Its rows are four measures, taken in each zone.
| Measure | Unit | How to read it |
|---|---|---|
| Follicle count per cm² | Follicles per square centimeter | How many follicles appear in one square centimeter of scalp |
| Average hairs per follicular unit | Hairs per group | Scalp hair grows in small natural groups called follicular units; this is the average number of hairs per group |
| Average hair width | Micrometers (µm) | The average thickness of the strands measured; one micrometer is a millionth of a meter, or a thousandth of a millimeter |
| Terminal to vellus ratio | A ratio | How the number of terminal hairs (thick, coarse, usually longer and darker) compares with the number of vellus hairs (fine, thin, usually shorter and lighter) |
The values on your report are your own, taken from your own assessment. This page gives no target numbers, on purpose. Each reading documents the appearance of your hair and scalp on the day it was taken, and the comparison that means something is with your own earlier readings.
During a head spa, the analysis on screen also looks at oil and hydration balance, buildup along the root line, and the condition of the skin. For what the analysis is and is not, see the scalp analysis page.
How is each number captured?
- Same zones, same way. The three zones are captured the same way every visit, so each session can be set beside the last.
- Magnified images. The spa uses the Canfield VEOS HairMetrix system. Canfield lists the magnification of its VEOS device as 12.5x.
- No clipping. Canfield Scientific states that HairMetrix analysis requires no hair clipping.
- Automated analysis. Canfield describes HairMetrix as fully automated, real-time analysis.
- On screen, together. You see the images and the report on screen. The analysis takes about four minutes.
How do you compare one visit with the next?
- Match the zone. Compare temporal with temporal, vertex with vertex, and occipital with occipital.
- Match the measure. Read one row at a time: the same measure, visit after visit.
- Match the moment. Each head spa ritual has a reading at the start and another at the end. To compare visits, set the start of one visit beside the start of the next, and the end beside the end.
- Read several visits together. One pair of readings tells you less than a run of them, taken the same way.
- Keep your photos. Every ritual includes a post treatment scalp photo for your records, and most guests ask the team to send them their photos.
At The Hair Lab, the scalp analysis comes first, before The Root Method™ begins. Individual results vary and are not guaranteed.
What can change a reading from one visit to the next?
Readings compare most cleanly when they are taken the same way. The National Institute of Standards and Technology calls this repeatability: how closely the results of successive measurements of the same thing agree under the same conditions, meaning the same procedure, the same observer, the same instrument, the same location, and repetition over a short period of time. Its separate term for measurements taken under changed conditions is reproducibility.
- Where the image is taken. That is why the spa captures the same three zones the same way every visit.
- When in the visit it is taken. The first reading comes before the cleanse and exfoliation. The second comes after them.
- The appearance of your hair and scalp. Documenting it, visit by visit, is what the analysis is for.
The scalp analysis measures appearance and is not used to identify or assess any medical condition. If you have a medical concern about your hair or scalp, please consult a licensed physician.
What does a scalp analysis report not tell you?
- Not a medical finding. The scalp analysis is a cosmetic assessment, and it is not used to identify or assess any medical condition.
- Not a grade. The Root & Scalp Spa does not publish target numbers. Your report shows your own values, for comparison with your own earlier visits.
- Not a forecast. The analysis documents how your hair and scalp look on the day. It does not predict how they will look later.
- Not a promise. Individual results vary and are not guaranteed.
What else do people ask about scalp analysis reports?
What is a good follicle count per cm²?
The Root & Scalp Spa does not publish target numbers for its scalp analysis. The analysis measures the appearance of your hair and scalp, and the useful comparison is your own reading against your own earlier visit, in the same zone. If you have a medical concern about your hair or scalp, please consult a licensed physician.
What does terminal to vellus ratio mean on a scalp analysis?
It compares how many terminal hairs appear with how many vellus hairs appear in the area measured. Terminal hairs are thick and coarse, usually longer and darker; vellus hairs are fine and thin, usually shorter and lighter. At The Root & Scalp Spa it is one of four measures in each of three zones, and it describes appearance.
What does µm mean on a scalp analysis report?
µm stands for micrometer, a unit of length equal to one millionth of a meter, or one thousandth of a millimeter. On a scalp analysis report at The Root & Scalp Spa, average hair width is given in micrometers: the average thickness of the hair strands measured.
Why is my scalp analysis different from last time?
Two readings compare most cleanly when they are taken the same way: the same zone, and the same point in the visit. At The Root & Scalp Spa the same three zones are captured the same way every visit, so each session can be set beside the last. The analysis measures appearance and is not used to identify or assess any medical condition.
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