When hair starts falling, the first instinct is often to book a blood test for hair fall, sometimes a large “hair fall package” from a lab or app. Many readers search for it as “hair fall ke liye kaun sa test”. The honest answer: a few tests help some people, and many are ordered without a reason.
For the types and causes of hair loss, start with our complete guide to hair loss in India.
Why a scalp examination comes before any blood test
A doctor diagnoses hair loss mainly by asking questions and looking at your scalp, not with a blood test. A 2024 review for family doctors in American Family Physician says tests for conditions such as thyroid disease, anaemia, vitamin D deficiency or syphilis “should be guided by the clinical evaluation”.
The pattern decides what, if anything, is worth testing:
- Typical pattern hair loss in men (a receding hairline or thin crown). A 2019 Indian expert consensus says laboratory tests are usually not needed, especially in men.
- Sudden, diffuse shedding after a fever, childbirth or crash diet. The trigger usually explains it; see hair fall after fever, dengue, coronavirus disease (COVID) or a crash diet.
- Diffuse shedding with no obvious cause. This is where a small set of blood tests is most useful.
- Thinning in women with irregular periods, acne or excess facial hair. Hormone tests may help.
- Patchy, scaly or scarring loss. These usually need a scalp scraping or biopsy rather than blood tests.
Blood tests for hair fall that can help, and when
For diffuse shedding without an obvious cause, a 2009 review in the Indian Journal of Dermatology, Venereology and Leprology (IJDVL) says a complete blood count, serum ferritin and thyroid tests should be checked. Its reason: iron deficiency and thyroid disorders are common, and often cause no other obvious signs.
Complete blood count (haemoglobin)
This checks for anaemia. It matters in India: the National Family Health Survey (NFHS-5, 2019–21) found anaemia in 57.0% of women and 25.0% of men aged 15–49. A normal haemoglobin does not rule out low iron stores, which is why ferritin is often checked alongside it.
Serum ferritin
Ferritin reflects your iron stores. It is useful when shedding is diffuse and unexplained, especially with heavy periods or tiredness. Guo and Katta (2017) also list a vegetarian diet as a risk factor, because iron from plants is absorbed less well.
TSH (thyroid-stimulating hormone)
Both an underactive and an overactive thyroid can thin hair. Doctors usually start with TSH and add thyroxine (T4) or triiodothyronine (T3) if needed. The American Family Physician review also suggests considering thyroid screening in people with alopecia areata (round bald patches), because autoimmune thyroid disease can accompany it. Our guide to TSH, T3 and T4 levels explains how to read the report.
Hormone tests in women
The IJDVL review advises hormone screening in women with signs of high androgens (hormones such as testosterone), including excess facial or body hair, severe acne or irregular periods, and in women whose thinning is sudden, rapid or severe. Its minimum tests are testosterone and/or dehydroepiandrosterone sulfate (DHEAS), with prolactin and others in a fuller panel. The Indian expert consensus agrees that women with pattern hair loss may be tested for testosterone, DHEAS, insulin and prolactin. If your periods are irregular, see irregular periods and polycystic ovary syndrome (PCOS): when to worry.
Vitamin D, vitamin B12 and zinc
The evidence for each of these is weaker.
- Vitamin D. The American Family Physician review includes vitamin D when a doctor diagnoses telogen effluvium (shedding after a trigger). A 2019 review by Almohanna and colleagues says the link between vitamin D and common hair loss “is still being debated”, though most authors would supplement a proven deficiency.
- Vitamin B12 and folate. The same review says there is too little evidence to recommend screening for them in shedding or pattern hair loss.
- Zinc. Almohanna and colleagues say data are too inconsistent to recommend zinc screening in these types of hair loss. Guo and Katta (2017) add that serum zinc is affected by several variables, so a single result can mislead. Testing makes more sense with a real risk, such as a bowel condition that affects absorption, weight-loss surgery or heavy alcohol use.
Syphilis and autoimmune tests
Syphilis can cause hair loss, and so can autoimmune diseases such as lupus. The American Family Physician review lists both among the conditions to test for only when the clinical evaluation points to them. An antinuclear antibody (ANA) test (a screen for autoimmune disease) is not a routine hair fall test.
Ferritin: why the “normal” number depends on who you ask
There is no single agreed ferritin cut-off for hair loss. Sources use different numbers for different purposes, and some disagree about treatment. Ferritin is reported in ng/mL or µg/L, which are the same.
- World Health Organization (WHO) 2020 guideline. Ferritin below 15 indicates iron deficiency in apparently healthy adults. With infection or inflammation, below 70 may indicate deficiency, because inflammation raises ferritin and can hide low iron. WHO rates the evidence for the 70 cut-off as low certainty.
- The Indian IJDVL review (2009). Laboratories used cut-offs from 20 to 70, and one group of hair specialists treats until ferritin reaches 70. Yet the review finds insufficient evidence to screen everyone with hair loss for iron deficiency, or to treat low iron without anaemia.
- Almohanna and colleagues (2019). Studies defined iron deficiency anywhere from 15 or below to under 70. There is “no consensus on ‘normal ferritin’ levels”, and most authors supplement below about 40.
- Guo and Katta (2017). Whether low iron stores without anaemia cause hair loss is unknown; studies conflict. Two review groups they describe aim for above 50 or above 70.
What this means for you. To take an example, a ferritin of 30 may sit inside the normal range on your lab report, below a hair clinic’s target, and count as iron deficiency by WHO’s standard if you have an infection or inflammation. Read the number alongside haemoglobin and your recent health. Our judgement for Indian readers: let the doctor who examined your scalp decide whether a low-normal ferritin needs treatment. Do not take iron tablets to chase a number; too much iron causes harm, and Guo and Katta note that anyone taking iron needs monitoring.
If ferritin is low, the next question is why. Guo and Katta name menstrual blood loss as the usual reason before menopause, and blood loss from the gut in men and older women, alongside diet. Our guide to foods for hair fall covers iron-rich Indian meals and how to absorb more iron.
Test-by-test summary
| Test | When it helps | When it usually does not | Source |
|---|---|---|---|
| Complete blood count | Diffuse, unexplained shedding; tiredness, paleness or heavy periods | Typical male pattern loss with no other symptoms | IJDVL 2009; Indian consensus 2019 |
| Serum ferritin | Diffuse, unexplained shedding, especially in women | As a target to chase with supplements; read with care during infection | IJDVL 2009; WHO 2020 |
| TSH (with T4 or T3 if needed) | Diffuse, unexplained shedding; thyroid symptoms; alopecia areata | Typical male pattern loss with no thyroid symptoms | IJDVL 2009; American Family Physician (AFP) 2024 |
| Testosterone, DHEAS, prolactin | Women with irregular periods, acne, excess hair, or sudden or severe thinning | Most men with pattern loss | IJDVL 2009; Indian consensus 2019 |
| Vitamin D | Telogen effluvium, or risk factors such as little sun exposure | As a routine test for every hair fall | AFP 2024; Guo and Katta 2017 |
| Vitamin B12, folate | When your doctor suspects deficiency for another reason | Routine screening for shedding or pattern loss | Almohanna 2019 |
| Zinc | Malabsorption, weight-loss surgery, heavy alcohol use | Routine screening for shedding or pattern loss | Almohanna 2019; Guo and Katta 2017 |
| Syphilis test, ANA | When history or examination points to infection or autoimmune disease | Routine hair fall work-up | AFP 2024 |
Which tests are overused, and why it matters
Large hair fall packages and routine vitamin D, zinc and B12 tests are the most common overuse. Guo and Katta advise that people with hair loss but no risk factors for a nutrient deficiency do not need laboratory tests for one.
A low result is not always the cause
Some tests come back “low” in most people, with or without hair loss. In a Turkish clinic study of 467 people tested for hair loss, vitamin D was reported deficient in 74% overall, including 65% of those in whom no hair-loss condition could be diagnosed. By contrast, low haemoglobin appeared in only 1% of that undiagnosed group. When a result is low in most people tested, it tells you little about your hair.
The Endocrine Society’s 2024 guideline, written for general health rather than hair, suggests against routine vitamin D testing in healthy adults without a specific reason. It says no level has been shown in trials to define benefit.
Supplements follow the report
A page of “low” results often leads to a bag of supplements. Too much iron or zinc causes its own harm, excess vitamin A or selenium can itself cause hair loss, and the real cause, such as pattern hair loss, may go untreated.
Hormone tests in men
The Indian expert consensus explains that male pattern baldness is not related to androgen levels in the blood, but to follicles that are genetically sensitive to normal levels. So a testosterone test in a man with typical thinning is usually normal and rarely changes the plan.
Before your blood test: biotin and other checks
Biotin can make lab results wrong. The US Food and Drug Administration (FDA) warns that biotin in blood samples can cause falsely high or falsely low results, depending on the test, including hormone tests such as thyroid tests. It notes that many hair, skin and nail supplements contain biotin at levels up to 650 times the recommended daily intake, sometimes without “biotin” in the product name.
- Tell your doctor and the lab about every supplement, including multivitamins, “hair gummies” and prenatal vitamins.
- Pause biotin only as your doctor advises. The FDA says data are insufficient to set a safe waiting time, so there is no fixed rule to follow on your own.
- Mention any recent fever or infection, since it can raise ferritin for a while.
- If you are pregnant, say so: WHO notes that pregnancy makes a single ferritin cut-off hard to set.
When to see a doctor
These are the main warning signs; our hub has the full list of hair-loss red flags.
Emergency: get help now
- A painful, swollen or pus-filled scalp patch with fever or feeling very unwell.
- Sudden heavy hair loss with vomiting, confusion, or numbness or weakness in the hands or feet.
- Thoughts of harming yourself. Call 112 or Tele Mental Health Assistance and Networking Across States (Tele-MANAS), the Government of India’s mental-health helpline (14416).
Prompt review: within days to a few weeks
- Round bald patches, or patches that are red, scaly, painful or smooth and shiny.
- Sudden heavy shedding with no obvious trigger.
- Hair loss with tiredness, breathlessness, paleness, heavy periods, weight change or feeling unusually cold or hot.
- Irregular periods, acne, excess facial hair or a deepening voice with thinning hair.
- Skipping meals, severe food restriction or fear of eating.
Routine review
- Gradual thinning, a widening parting or a receding hairline.
- Shedding after illness or childbirth that has not settled after six months.
- A report with “low” results that you want explained, before you buy any supplement.
How Disha can help
Disha is an AI health coach that chats and calls in Hindi, English and Hinglish. It does not order or interpret blood tests, diagnose hair loss, prescribe supplements or provide emergency care, and it does not replace your doctor. If your doctor finds low iron or advises better eating, Disha can help you build iron- and protein-rich Indian meals and keep up sleep and movement. Read how Disha coaching works.
This is not medical advice. This page is general education for adults (18+), not a diagnosis or treatment plan. Hair loss in children needs a doctor’s assessment. Do not start, stop or change any medicine or supplement, including iron or biotin, because of this page or a lab report alone. If you are pregnant, breastfeeding, or have a current or past eating disorder, get individual advice.
Frequently asked questions
Which blood test is best for hair fall?
There is no single best test. For diffuse shedding without an obvious cause, doctors commonly check a complete blood count, serum ferritin and TSH. Women with irregular periods, acne or excess facial hair may need hormone tests. Men with typical pattern thinning usually need no blood tests at all. A scalp examination comes first and decides which tests, if any, are worth doing.
What ferritin level is normal for hair?
There is no agreed number. WHO defines iron deficiency in healthy adults as ferritin below 15, or below 70 with infection or inflammation. Hair studies have used cut-offs from 15 to 70, and some specialists treat below about 40 or aim for 50 or 70, but evidence for treating low ferritin without anaemia is debated. Ask your doctor to read it alongside haemoglobin.
Should I do a full hair fall package test?
Usually not. A dermatology review by Guo and Katta advises that people with hair loss but no risk factors for a nutrient deficiency do not need tests for one. Tests such as vitamin D can come back “low” in most people, with or without hair loss, so they may not explain your hair fall and can lead to unnecessary supplements. A doctor’s examination usually points to two or three useful tests at most.
Can vitamin D deficiency cause hair fall?
Possibly, but the link is still debated. Some studies find lower vitamin D in people with hair loss, yet low levels are also very common in people without it. A doctor may test vitamin D if shedding follows a trigger or you get little sun. Most experts would treat a proven deficiency, but the evidence that extra vitamin D regrows hair otherwise is limited and still debated.
Does biotin affect blood test results?
Yes. The US FDA warns that biotin can make some lab tests, including hormone tests such as thyroid tests, read falsely high or falsely low. Many hair, skin and nail supplements contain large amounts. Tell your doctor and the lab about any supplement you take, and pause biotin before testing only as your doctor advises, since no fixed waiting time has been agreed.
Do men need a testosterone test for hair loss?
Usually not. In male pattern hair loss, blood hormone levels are typically normal; the follicles are simply more sensitive to them. An Indian expert consensus says laboratory tests are usually not needed for pattern hair loss, especially in men. A doctor may test hormones if there are other symptoms, but a normal testosterone result does not rule out pattern hair loss.
My ferritin is low but haemoglobin is normal. Should I take iron?
Ask your doctor first. Low iron stores without anaemia are common, especially in women with heavy periods, but whether they cause hair fall is debated, and an Indian review found insufficient evidence to treat them in hair loss. Your doctor may still advise treatment and will look for the reason iron is low. Do not start iron tablets on your own.
Sources
- Shrivastava SB. Diffuse hair loss in an adult female: Approach to diagnosis and management. Indian Journal of Dermatology, Venereology and Leprology, 2009. Review. Supports: complete blood count, serum ferritin and thyroid tests for diffuse hair loss without a discernible cause, because iron deficiency and thyroid disorders often have no other signs; hormone screening in women with signs of high androgens or sudden, rapid or severe thinning, and the tests listed; ferritin cut-offs of 20 to 70 and treating to 70 in one specialist group; insufficient evidence for universal iron screening or for treating low iron without anaemia.
- Mysore V, Parthasaradhi A, Kharkar RD, Ghoshal AK, Ganjoo A, Ravichandran G, Saraswat A, Shah Y, Singh M, Remadevi TJ, Matte P. Expert consensus on the management of Androgenetic Alopecia in India. International Journal of Trichology, 2019. Expert consensus. Supports: laboratory tests usually not needed in pattern hair loss, especially in men; male pattern baldness not related to blood androgen levels; testosterone, DHEAS, insulin and prolactin in women with pattern hair loss.
- Dakkak M, Forde KM, Lanney H. Hair Loss: Diagnosis and Treatment. American Family Physician, 2024. Clinical review. Supports: testing for thyroid disease, anaemia, vitamin D deficiency, autoimmune disease or syphilis guided by the clinical evaluation; vitamin D in the work-up of telogen effluvium; thyroid screening considered in alopecia areata.
- Guo EL, Katta R. Diet and hair loss: effects of nutrient deficiency and supplement use. Dermatology Practical & Conceptual, 2017. Narrative review. Supports: no nutrient testing without risk factors; vegetarian diets, menstrual and gut blood loss as iron risk factors; inflammation raising ferritin; the unknown effect of low iron stores without anaemia; ferritin targets above 50 or 70 in two review groups; monitoring anyone taking iron; serum zinc affected by several variables and risk factors for zinc deficiency; limited vitamin D data.
- Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatology and Therapy, 2019. Review. Supports: ferritin definitions from 15 or below to under 70, no consensus on normal ferritin, supplementing below about 40; the vitamin D link still debated; zinc, B12 and folate screening not recommended in shedding or pattern hair loss; biotin interference with thyroid and sex-hormone tests.
- World Health Organization. WHO guideline on use of ferritin concentrations to assess iron status in individuals and populations: executive summary. 2020. Guideline. Supports: ferritin below 15 µg/L for iron deficiency in apparently healthy adults; below 70 µg/L with infection or inflammation (conditional recommendation, low certainty); inflammation raising ferritin; difficulty setting a cut-off in pregnancy.
- Demay MB, Pittas AG, Bikle DD, et al. Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology & Metabolism, 2024. Guideline. Supports: suggesting against routine vitamin D testing in healthy adults without established indications; no trial-based vitamin D levels defining benefit.
- Öner Ü, Akdeniz N. Nonscarring scalp alopecia: Which laboratory analysis should we perform on whom? Turkish Journal of Medical Sciences, 2022. Retrospective observational study. Supports: vitamin D deficiency in 74% of 467 people tested for hair loss and 65% of those with no diagnosable hair-loss condition; low haemoglobin in 1% of that group.
- US Food and Drug Administration, republished by the American Society of Anesthesiologists. Biotin (Vitamin B7): Safety Communication – May Interfere with Lab Tests. 2017. Safety communication. Supports: falsely high or low results including hormone tests; hair, skin and nail supplements with biotin up to 650 times the recommended intake, not always clear from the name; telling the doctor and lab; insufficient data on how long biotin takes to clear.
- International Institute for Population Sciences and Ministry of Health and Family Welfare. National Family Health Survey (NFHS-5) 2019–21: India Fact Sheet. 2021. National survey. Supports: anaemia in 57.0% of women and 25.0% of men aged 15–49.
Related reads
- Hair loss in India: causes, tests, treatment and daily care: the full overview of every type of hair loss; this page goes deeper on blood tests only.
- Foods for hair fall: iron, protein and the Indian thali: what to eat if a test shows low iron, and honest verdicts on hair supplements.
- Hair fall after fever, dengue, COVID or a crash diet: why shedding starts months after a trigger, and when it needs tests.
- TSH, T3 and T4 levels explained: how to read a thyroid report if your doctor orders one.
- Irregular periods and PCOS: when to worry: for women whose thinning comes with irregular periods, acne or excess hair.
- All hair loss articles: every Disha guide on hair fall and thinning.
- Calorie counter for Indian household servings: check you are eating enough, since low intake can drive both low iron and shedding; values are estimates.
