Hair Loss Diagnosis and Testing

The medical history is the first and most essential diagnostic tool in the hands of the dermatologist. The accurate diagnosis of hair loss is largely guided by the information obtained during the clinical interview. The dermatologist examines when the loss started, how quickly it is progressing and whether it is localized or diffuse throughout the scalp. They also investigate possible associated complaints, such as redness, itching, pain or scaling, as well as recent potential triggering factors, such as stress, infection, pregnancy/childbirth, diet, medication or styling practices. At the same time, they evaluate any hormonal disorders and family history of alopecia.

Based on the patient’s answers, the dermatologist decides which tests will be needed to confirm or rule out the underlying cause.

Trichoscopy is a quick, non-invasive technique that uses a dermatoscope – a high-resolution imaging tool, which allows the dermatologist to identify features that are not visible to the naked eye, such as changes in the hair shaft, hair follicles and blood vessels, as well as signs of inflammatory or scarring forms of alopecia that require immediate intervention. In some cases, it reduces the need for biopsies.

Today, the examination is performed mainly with digital trichoscopy, where a high-resolution camera is connected to a computer, which records and objectively analyzes the findings with the help of specialized software that allows comparison of data, for accurate monitoring of response to treatment over time.

The classic trichogram is a microscopic examination where the dermatologist carefully removes a small number of hairs from various points on the scalp and examines them under a microscope, in order to determine the percentage of anagen (actively growing) and telogen (shedding) hairs. This ratio helps distinguish between telogen effluvium and androgenetic alopecia, as well as monitoring progress after treatment.

The phototrichogram is the modern, digital variant of the same examination. With a special high-resolution camera and software, it records hair density per square centimeter, diameter, as well as the percentage of anagen and telogen hairs. The procedure is painless and is repeated at intervals for comparison of results and monitoring of treatment effectiveness.

The pull test is a simple and quick examination that helps the doctor assess whether there is active hair loss. During the procedure, the doctor grasps a small bundle of about 50 hairs from different points on the scalp and applies gentle traction. If more than 5-6 hairs are dislodged, it is an indication that there is an active phase of hair loss, such as in telogen or inflammatory form. Conversely, when only 1-2 hairs are dislodged, the test suggests a stable condition, as usually occurs in androgenetic alopecia without exacerbation.

The examination is painless and immediate, but its result must be interpreted in combination with trichoscopy, history and other tests, as it is affected by factors such as washing or combing before the visit. Although it is not a diagnostic method by itself, it helps assess whether the loss is in an active phase and which form of hair loss should be further investigated.

Follysis is a digital scalp analysis tool that provides accurate and up-to-date data on hair condition through regular checks. Using a special high-resolution camera and advanced software, it records the density, diameter and quality of hair, as well as the ratio of anagen and telogen follicles at different points on the head.

This technology allows the creation of a digital scalp profile, with quantitative data, in order to accurately monitor the course of treatment over time. Repeated measurements make it possible to compare results before and after treatment, providing an objective picture of improvement.

Follysis analysis is now an integral tool of the diagnostic and therapeutic process in modern hair restoration clinics, as it combines accuracy, speed and reliability in assessing the actual condition.

Genetic testing is a simple and modern way to determine if someone has a genetic predisposition for hair loss, such as androgenetic alopecia. With a special swab (stylus), the dermatologist collects a saliva sample from inside the mouth or with a blood sample, which is sent to a laboratory for analysis. During the examination, 48 genetic variations in 13 genes related to follicle sensitivity to androgens, thinning rate and future progression of hair loss are analyzed.

Based on the results, the doctor creates a personalized prevention or treatment program, adapted to each person’s genetic profile, and the patient is directed from the beginning towards the most appropriate and effective options, saving time and cost.

Scalp biopsy is performed when the cause of hair loss cannot be determined with other tests or when there is suspicion of scarring alopecia. During the procedure, the dermatologist removes a very small sample of skin from the scalp, usually from the area where thinning is most pronounced. The sample is examined histologically under a microscope, in order to evaluate the condition of the follicles, the presence of inflammation or fibrosis and the type of lesion.

The examination is done with local anesthesia, is painless and safe, and provides valuable information for distinguishing between scarring and non-scarring forms of alopecia. The biopsy results help the doctor identify the exact cause and choose the most appropriate therapeutic approach, especially in rare or complex cases.

Certain medications are responsible for transient or persistent hair loss as a side effect. In these cases, the diagnosis is based mainly on medical history and not on hematological tests. The dermatologist will ask if there is a temporal correlation between the start of drug therapy and the onset of hair loss.

Drugs that are most commonly implicated include chemotherapy drugs (usually causing sudden loss, anagen effluvium), anticoagulants, certain antidepressants and mood stabilizers, blood pressure medications (beta-blockers) and systemic retinoids (for acne/psoriasis).

Usually, hair loss gradually subsides after discontinuation of the offending drug, always in consultation with the treating physician.

The complete blood count (CBC) is the basis of any initial investigation. Its most important contribution to the diagnosis of alopecia is the exclusion of anemia, which reduces oxygen transport to the hair follicles, hindering hair growth and leading to diffuse hair loss.

Ferritin is the protein that stores iron in the body and releases it when needed. Low ferritin levels have been associated with diffuse hair loss, especially in women of reproductive age, vegetarians or people with malabsorption.

While the laboratory’s “normal” reference ranges may be different (e.g., starting from 10 or 20 μg/mL), specifically for treating hair loss, dermatologists recommend that ferritin levels be at least 50 μg/mL, with an ideal target range of 50-70 μg/mL, to support optimal hair growth.

Vitamin D regulates cell division and immune system function, which contribute to cell multiplication and proper tissue renewal. Its deficiency is particularly common in people with hair loss and has been linked to autoimmune forms, such as alopecia areata.

Checking its levels is considered justified due to its crucial role in hair follicle health and the high frequency of deficiency observed in the general population, due to limited sun exposure in modern lifestyle.

Vitamins B12 and B9 are essential for DNA synthesis and normal cell division. Their deficiency has been linked to diffuse telogen effluvium, often accompanied by macrocytic anemia (red blood cells enlarge without dividing) or fatigue.

Their testing is recommended in people with a history of malabsorption, strict vegetarianism, restrictive diets or taking medications that affect the absorption of B vitamins.

Zinc participates in keratin synthesis and cell division. Its deficiency, although rare as a primary cause, has been linked to brittle hair and various forms of alopecia.

Measurement of zinc, as well as other second-line trace elements, such as selenium, copper or vitamin A, is indicated in persistent diffuse hair loss, history of malnutrition or malabsorption, but is not a first-line test.

Thyroid gland disorders are a recognized cause of hair loss, as its hormones regulate the life cycle and renewal of hair follicles. Both hypothyroidism and hyperthyroidism can cause diffuse hair loss or hair thinning.

Testing with measurement of TSH, FT4 and FT3 hormones is recommended in almost every new patient case, especially when there are symptoms such as fatigue, weight changes, mood swings or scalp dryness.

The determination of androgens is not only for men, but also for women who present with androgenetic alopecia-type thinning, especially when there are signs of hyperandrogenism, such as acne, hirsutism or menstrual disorders. Increased androgen levels compared to estrogens in women may indicate polycystic ovary syndrome (PCOS), one of the most common endocrinological causes of hair loss.

Testing includes total and free testosterone, DHEA (indicator of adrenal function) and SHBG, a protein that binds steroid hormones in the blood. When SHBG is low, free testosterone increases, which can affect hair growth and accelerate androgenetic-type thinning.

For reliable results, women should undergo testing in the early phase of the cycle (days 4-7), while any hormonal contraceptives should be discontinued at least eight weeks before sampling.

Elevated prolactin (hyperprolactinemia) can disrupt hormonal balance, indirectly affecting hair growth, with the appearance of hair loss or, more rarely, hirsutism.

Its measurement is recommended when menstrual disorders, galactorrhea or other endocrinological findings coexist, as it may indicate hypothalamic or pituitary dysfunction or drug etiology.

Disorders of glucose metabolism and insulin resistance can worsen hormonally induced hair loss, especially in female-type androgenetic alopecia. Hyperinsulinemia stimulates androgen production by the ovaries, which intensifies hair follicle shrinkage.

Testing includes fasting glucose (measurement of sugar after 12-hour abstinence from food) and lipid profile (cholesterol, LDL, HDL, triglycerides), as part of the assessment for metabolic syndrome. It is recommended in patients with obesity, insulin resistance or suspected PCOS in women.

These tests are requested when there is suspicion of an inflammatory or autoimmune cause. Elevated CRP (C-reactive protein) or ESR (Erythrocyte Sedimentation Rate) values indicate active inflammation, while positive ANA (Antinuclear Antibodies) may indicate autoimmune diseases such as lupus erythematosus, which can lead to scarring, permanent hair loss.

Investigation is recommended when hair loss is accompanied by redness, scaling or pain on the scalp, as well as when general symptoms such as fatigue or arthralgia coexist.

Cortisol is the main stress hormone and plays a role in regulating metabolism and the immune system. Although chronic stress has been proven to contribute to telogen effluvium, cortisol testing is only needed when there are signs of endocrinological disorder, such as Cushing’s syndrome or adrenal insufficiency.

Hair loss can in some cases be related to infections or exposure to toxic substances. Syphilis, although rare today, can cause characteristic-type alopecia and should be ruled out with serological testing (biochemical and hematological tests).

Exposure to heavy metals, such as lead or mercury, can affect hair follicle function and cause diffuse hair loss. Relevant testing is done only when there is documented history of occupational or environmental exposure.

Disorders of glucose metabolism and insulin resistance can worsen hormonally induced hair loss, especially in female-type androgenetic alopecia. Hyperinsulinemia stimulates androgen production by the ovaries, which intensifies hair follicle shrinkage.

Testing includes fasting glucose (measurement of sugar after 12-hour abstinence from food) and lipid profile (cholesterol, LDL, HDL, triglycerides), as part of the assessment for metabolic syndrome. It is recommended in patients with obesity, insulin resistance or suspected PCOS in women.