**Hair Loss Diagnosis Process: From Consultation to Dermoscopy to Laboratory Tests**
There are many causes of hair loss, and accurate diagnosis is the first step toward effective treatment.
Doctors typically follow the sequence of “consultation → dermoscopy → laboratory tests” to narrow down the possibilities step by step.
The following content outlines this process for your reference only and does not constitute medical advice.
—
**Step 1: Consultation – Understanding Your Hair Loss Story**
The doctor will first take a detailed medical history. This may sound simple, but it is the most important step.
Information you need to provide includes: how long the hair loss has lasted, whether it appeared suddenly or worsened gradually, and approximately how many hairs you lose each day.
The doctor will also ask about the area where hair thinning occurs (crown, forehead, or entire scalp) and whether it is accompanied by scalp itching or pain.
In addition, recent stress events such as fever, surgery, drastic weight loss, or childbirth—which may trigger telogen effluvium—should be mentioned.
A family history of similar hair loss is crucial for diagnosing androgenetic alopecia (commonly known as “seborrheic alopecia”).
Medication history (e.g., contraceptives, antidepressants, chemotherapy drugs) and lifestyle factors (e.g., tight hairstyles, frequency of dyeing or perming) must also be disclosed truthfully.
—
**Step 2: Dermoscopy – Examining the Scalp and Hair Follicles with a “Magnifying Glass”**
Dermoscopy is a special device equipped with a light source and magnifying lens that allows non-invasive observation of the scalp surface and hair follicle openings.
The doctor applies a small amount of gel to your scalp, then places the dermoscope lens close to it; within seconds, a clear magnified image appears.
Through dermoscopy, it is possible to assess whether the follicle openings are normal, whether hair shaft diameters are uniform, and whether there are broken hairs or exclamation-mark hairs (indicating alopecia areata).
A typical sign of androgenetic alopecia is follicular miniaturization—a follicle that once produced 2–3 hairs now yields only a single, fine vellus hair.
Dermoscopy can also help rule out specific conditions such as tinea capitis (showing comma-shaped hairs) or discoid lupus erythematosus (accompanied by follicular keratotic plugs).
This exam is painless, quick, and one of the most commonly used diagnostic tools in outpatient clinics.
—
**Step 3: Laboratory Tests – From Blood to Pathology**
If the consultation and dermoscopy still cannot clarify the cause, the doctor may recommend laboratory tests.
The most common blood tests include: complete blood count (to rule out anemia-related hair loss), ferritin (to assess iron stores), and thyroid function (both hyperthyroidism and hypothyroidism can cause hair loss).
For women, a sex hormone panel (e.g., androstenedione, free testosterone) helps evaluate endocrine issues such as polycystic ovary syndrome.
If an autoimmune disease is suspected, tests for antinuclear antibodies (ANA) or anti-thyroid antibodies may be performed.
Deficiencies in vitamin D, zinc, selenium, and other micronutrients may also be linked to hair loss, but screening should be based on clinical indications rather than routine practice.
In rare cases, a scalp biopsy may be necessary—a small piece of scalp tissue is taken and analyzed under a microscope to differentiate scarring alopecia or special types of alopecia areata.
Biopsy is an invasive procedure and is only considered when the aforementioned methods fail to provide a diagnosis.
—
**Summary and Reminders**
The entire diagnostic process follows a principle of progressing from simple to complex: first non-invasive, then invasive; first subjective inquiry, then objective testing.
Most common types of hair loss (e.g., androgenetic alopecia, telogen effluvium) can be diagnosed through consultation combined with dermoscopy, without requiring additional lab work.
Laboratory tests are mainly used to investigate underlying internal diseases and are not necessary for every person experiencing hair loss.
If you experience unexplained heavy hair shedding, scalp redness, swelling, or scarring, or accompanying systemic symptoms (such as fatigue or weight loss), please seek medical attention promptly.
**For reference only, not medical advice.**
If you are troubled by hair loss, it is recommended to visit a dermatology department at a正规 hospital for a personalized evaluation by a physician.