Insight 24

Can AI diagnose hair loss from a photo?

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A photograph can show a widening part or a receding hairline. AI can help analyze images, count hairs and suggest possible explanations. The useful question is what the particular system has been tested to do and how its result will guide your care.

An AI-assisted result becomes more useful when the images, health history and scalp findings are considered together. You should be able to understand what was measured, what the result means and who reviewed it.

Start with the image

A phone photograph shows overall coverage. A standardized photograph makes comparisons more consistent. Trichoscopy provides a magnified view of hairs and scalp structures. A phototrichogram follows a small, prepared area to measure particular features of growth.

Each image answers different questions. A system trained on close-up scalp images needs testing before its performance can be assumed for ordinary selfies. Lighting, focus, styling, hair fibers and scalp visibility can also change the information available. Validation should cover the conditions in which the system will be used.1

Separate counting from diagnosis

Automated counting can make detailed image analysis faster. One published study developed a system to count and measure hairs in phototrichograms and compared its results with a human-assisted method. That supports a defined measurement task.2

Diagnosing the cause of loss asks a broader question. The explanation needs to account for the pattern, symptoms, time course and other findings. A system that measures density may have no tested ability to distinguish pattern hair loss from an inflammatory or scarring disorder.

The value of an AI result depends on the question it was tested to answer.

Find out what the performance claim covers

A claim of high accuracy needs context. Who established the reference diagnosis? Which conditions were included? Was the system tested on new patients, outside the material used to develop it? People with different skin tones, hair colors and hair textures should be represented in testing relevant to their use.1,3

A study comparing public AI chatbots with dermatologists on trichoscopy cases found that the tested chatbots performed less well. This was a study of particular systems and cases. It illustrates why each tool needs evidence for its intended task.4

Bring the missing history into the assessment

A photograph leaves many details outside the frame. Recent shedding, scalp pain, medication changes, restrictive eating and eyebrow loss can change the interpretation. Previous biopsy reports and laboratory findings may add information that an image cannot supply.

Ask what information the system receives and how conflicting findings are reviewed. A useful report should explain when image quality is inadequate or further assessment is needed. It should also make clear who is responsible for the next recommendation.1,3

Know how your images will be used

Before uploading, check who can access your photographs, how long they are stored, whether they can be used to train a model and whether you can request deletion. Clinical software and public apps can have different arrangements. Read the terms for the service you are considering.

Keep the original images and report if you want the result reviewed. At FHI, I assess how measurements and suggested explanations fit the case. The next step should follow from the combined findings, with a clear reason for any further examination or investigation.

References

  1. Health Canada, FDA and MHRA. Good machine learning practice for medical device development: Guiding principles. 2021. Return to text ↑
  2. Sacha JP, et al. Development and qualification of a machine learning algorithm for automated hair counting. Int J Cosmet Sci. 2021;43 Suppl 1:S34–S41. doi:10.1111/ics.12735. Return to text ↑
  3. Health Canada, FDA and MHRA. Transparency for machine learning-enabled medical devices: Guiding principles. 2024. Return to text ↑
  4. Publicly Available Large Language Models for Trichoscopy: A Head-to-Head Comparison with Dermatologists. Diagnostics. 2026;16:169. doi:10.3390/diagnostics16010169. Return to text ↑

Medical disclaimer: FHI Insights is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Consult a licensed healthcare professional regarding individual health concerns or treatment decisions.