Why is my hair falling out?

Not all hair loss means the same thing: sometimes it is a temporary loss and, other times, a progressive pattern that should be identified and discussed with your specialist.

Summary in 60 seconds

• Hair loss does not have a single cause: it can be related to genetics, hormones, postpartum, diseases, physiological stress, drugs or nutritional deficiencies.
• An important clue is the pattern : it’s not the same to see more hair in the shower as it is to notice a wider part or round patches without hair.
• If the hair loss started 2–3 months after childbirth, a high fever, surgery, an infection, or a period of great stress, it usually points to telogen effluvium .
• If hair loses density slowly, with a widening of the part or receding hairline, the common cause is a hereditary pattern .
• Alopecia areata usually presents as round patches and can affect eyebrows, eyelashes, or beard; it is an autoimmune, not infectious, cause.
• Some people need to rule out low iron, thyroid disorders, or other deficiencies ; not everyone needs the same tests.
• Taking biotin, iron, or zinc «just in case» is not a good strategy: it may not help and, in some cases, cause problems or interfere with laboratory tests.
• A consultation is important when there are plaques, inflammation, pain, scaling, rapid hair loss, or progressive thinning.

What is it?

“My hair is falling out” can describe two distinct situations. The first is the shedding of more hair than usual over a period of time; the second is a gradual loss of density because certain follicles are producing increasingly finer hairs. Distinguishing between these two things greatly changes the interpretation of the problem. Telogen effluvium is usually a diffuse and reactive hair loss; androgenic alopecia, or hereditary pattern hair loss, is usually slower and more progressive. Shrivastava 2009 , Ntshingila 2023 , BAD 2024

It’s also worth remembering that hair grows in cycles. When an injury disrupts this cycle, many follicles enter a resting phase, and the hair falls out weeks or months later. This explains why sometimes the real cause occurred long before we notice it. BAD 2025 , Rebora 2019

Why does it appear?

The most frequent cause of progressive hair loss is genetics , along with the sensitivity of the follicles to androgenic hormones. In men, it usually manifests as a receding hairline and a thinning crown; in many women, as diffuse thinning and an increasingly visible parting. It is not a “lack of care”: it is a common biological condition. Ntshingila 2023 , BAD 2024

Another very common cause is telogen effluvium , a reactive hair loss. It can occur after childbirth, high fever, infection, surgery, rapid weight loss, restrictive dieting, significant stress, hormonal changes, or certain medications. It usually begins 2–3 months after the trigger, which leads many people to not connect the two. (Shrivastava 2009 , BAD 2025 , Hughes 2024)

The postpartum period deserves its own section because it is a major concern and, in most cases, falls squarely within the context of telogen effluvium. Estrogen levels drop after pregnancy, which can increase hair loss for a few months postpartum. The important thing to remember is that «seeing a lot of hair fall out» does not necessarily mean permanent damage to the follicle. (AAD 2025 , Hughes 2024)

There are also medical causes. Alopecia areata is autoimmune and usually produces round patches; thyroid disorders can be associated with thinning or diffuse hair loss; some scalp infections can cause scaling and even localized bald patches. (Ungar 2025 , BAD 2024 , Hussein 2023)

Medications can also play a role. Not all drugs do, but some have been linked to reactive hair loss, so it’s worth reviewing the timeline of when hair loss started, along with any treatments that were started or stopped months earlier. Hughes 2024

Finally, there are deficiencies . Low iron, low protein intake, and, in fewer cases, other deficiencies can contribute to hair loss. Caution is advised here: the fact that a deficiency may be associated with hair loss does not mean that every case of hair loss requires supplements, nor that taking them without medical evaluation will accelerate recovery. (Moeinvaziri 2009 , Almohanna 2019 , NIH SDGs 2025)

What does it look like and what symptoms does it cause?

Reactive hair loss is often seen as more hair on the pillow, comb, or in the shower, with a feeling of «I’m losing a lot of hair,» but without a completely bald patch. The hereditary pattern usually results in a slower loss of volume: a wider part in women, a receding hairline or thinning crown in men, or both, depending on the individual. Shrivastava 2009 , BAD 2024

When round patches , loss of eyebrows or eyelashes, or well-defined areas of hair loss appear, the suspicion changes, and alopecia areata should be considered. If there is also intense itching, pain, burning, crusting, pus, or marked scaling, inflammation or infection of the scalp should be evaluated. BAD 2024 , AAD 2022

What should I do?

Start by observing the pattern and timing . Ask yourself if the hair loss began abruptly or gradually, and if there was childbirth, fever, surgery, infection, weight loss, a change in birth control, significant stress, or new medication in the previous 2–3 months . This temporal reconstruction is far more helpful than simply counting how many hairs were left in the brush on a single day. Shrivastava 2009 , BAD 2025 , Hughes 2024

The best-supported advice is this: avoid very restrictive diets, ensure sufficient protein intake, avoid hairstyles that pull on the hair, consult a doctor if the pattern suggests alopecia areata or progressive hair loss, and seek professional evaluation before starting any treatments or supplements. In hereditary hair loss or in some selected cases, a dermatologist may suggest options such as minoxidil; in others, the primary approach is to identify and eliminate the trigger. AAD 2022 , BAD 2024

Don’t attribute every hair loss to «stress» without examining the pattern. Don’t stop taking medications on your own. Don’t start iron, zinc, or biotin «just in case» without a clinical or laboratory reason. And don’t continue wearing tight hairstyles, using harsh straightening treatments, or following routines that irritate your scalp for months while you try to figure out the cause. Hughes 2024 , Patel 2017 , AAD 2022

When should I consult?

Consult a dermatologist if any of these signs appear:

• fall in plates or round areas

• loss of eyebrows, eyelashes or beard

• pain, burning, intense itching , scabs, pus or significant peeling

• a very rapid drop in blood pressure following a major illness or accompanied by marked fatigue, paleness, menstrual irregularity, weight changes, or thyroid symptoms

• progressive thinning of hair over weeks or months

• doubts about whether a medication or a deficiency might be involved

These situations do not necessarily indicate a serious condition, but they do warrant a more careful evaluation to avoid overlooking treatable or, in some cases, inflammatory causes. AAD 2022 , BAD 2024 , Shrivastava 2009

Frequently Asked Questions

Can stress really make your hair fall out?

• Yes, but it usually acts as a trigger for telogen effluvium, not as the sole explanation for any hair loss. Typically, the hair loss appears weeks or months after the stressful event. (BAD 2025 , Hughes 2024)

Is it normal to lose hair after giving birth?

• Yes, in many women. It is often related to the drop in estrogen levels after pregnancy and is consistent with postpartum telogen effluvium. AAD 2025 , Hughes 2024

How do I know if what I have is genetic?

• This is suggested by a slow and progressive loss of density, with a wider parting, less volume, or a receding hairline, rather than a sudden, patchy hair loss. Even so, it’s advisable to confirm this because two causes can coexist. BAD 2024 , AAD 2022

Does biotin help?

• Only in very specific contexts. Biotin deficiency is rare, and the evidence for supplementing healthy individuals with hair loss is limited. Furthermore, high doses can alter some laboratory tests. Patel 2017 , NIH SDGs 2022

Do I need blood tests?

• Not everyone needs the same testing, but when the cause is not obvious, it is usually reasonable to assess iron and thyroid function, among other tests depending on the clinical context. Shrivastava 2009 , AAD 2022

How long does it take to get better?

• It depends on the cause. Reactive hair loss usually improves when the trigger is resolved, while hereditary hair loss tends to progress if left untreated. Therefore, the duration of the condition is very helpful in determining its course. BAD 2025 , Ntshingila 2023

Bibliography and sources

• Ntshingila S, Oputu O, Arowolo AT, Khumalo NP. Androgenetic alopecia: An update . JAAD Int 2023;13:150-158. doi:10.1016/j.jdin.2023.07.005.
• Shrivastava SB. Diffuse hair loss in an adult female: approach to diagnosis and management . Indian J Dermatol Venereol Leprol. 2009;75(1):20-27. doi:10.4103/0378-6323.45215.
• Rebora A. Telogen effluvium: a comprehensive review . Clin Cosmet Investig Dermatol. 2019;12:583-590. doi:10.2147/CCID.S200471.
• Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The Role of Vitamins and Minerals in Hair Loss: A Review . Dermatol Ther (Heidelb). 2019;9(1):51-70. doi:10.1007/s13555-018-0278-6.
• Patel DP, Swink SM, Castelo-Soccio L. A Review of the Use of Biotin for Hair Loss . Skin Appendage Disord. 2017;3(3):166-169. doi:10.1159/000462981.
• Moeinvaziri M, Mansoori P, Holakooee K, Safaee Naraghi Z, Abbasi A. Iron status in diffuse telogen hair loss among women . Acta Dermatovenerol Croatia. 2009;17(4):279-284.
• Carmina E, Azziz R, Bergfeld W, Escobar-Morreale HF, Futterweit W, Huddleston H, et al. Female Pattern Hair Loss and Androgen Excess: A Report From the Multidisciplinary Androgen Excess and PCOS Committee . J Clin Endocrinol Metab. 2019;104(7):2875-2891. doi:10.1210/jc.2018-02548.
• Ungar B, Renert-Yuval Y, Dlova NC, Jabbari A, King B, Mesinkovska NA, et al. Alopecia areata . Nat Rev Dis Primers. 2025;11(1):77. doi:10.1038/s41572-025-00664-9.
• British Association of Dermatologists. Telogen effluvium . Patient Information Sheetlet; Oct 2025. Retrieved March 16, 2026.
• British Association of Dermatologists. Alopecia areata . Patient Information Leaflet; April 2024. Retrieved March 16, 2026.
• British Association of Dermatologists. Hair loss female pattern (androgenetic alopecia) . Patient Information Sheetlet; Oct 2024. Retrieved March 16, 2026.
• British Association of Dermatologists. New British Association of Dermatologists’ living guideline for managing people with alopecia areata . Published 15 January 2025; revised 8 July 2025. Retrieved 16 March 2026.
• American Academy of Dermatology Association. Hair loss: Diagnosis and treatment . Accessed March 16, 2026.
• American Academy of Dermatology Association. Hair loss in new moms: Dermatologist tips . Accessed March 16, 2026.
• National Institutes of Health, Office of Dietary Supplements. Iron — Fact Sheet for Health Professionals . Updated September 4, 2025. Accessed March 16, 2026.