Why Is My Hair Falling Out? 15 Common Causes of Hair Loss & the Best Treatment Options

 

Table of Contents 1.  Why Is My Hair Falling Out? Understanding Normal vs Abnormal Shedding 2.  15 Common Causes of Hair Loss — Complete Breakdown 3.  How to Identify Which Cause Applies to You 4.  When to See a Specialist 5.  Best Treatment Options for Each Cause 6.  Advanced Clinical Treatments at Renaissance Clinic India 7.  Frequently Asked Questions 8.  References, Backlinks & Internal Linking Map

 

 

1. Why Is My Hair Falling Out? Understanding Normal vs Abnormal Shedding

Why is my hair falling out? This is one of the most frequently searched and most anxiety-inducing questions we encounter at Renaissance Clinic India — and for good reason. Hair carries enormous emotional and social significance, and noticing more strands than usual on your pillow, in the shower, or on your hairbrush can feel alarming, even when the cause turns out to be entirely manageable.

Before diving into specific causes, it helps to understand what is biologically normal. Every hair follicle on your scalp cycles independently through phases of active growth, transition, and rest, before the hair sheds and a new one begins growing in its place. Losing 50 to 100 hairs per day is considered entirely normal as part of this natural cycle — it is when shedding significantly exceeds this baseline, or when it is concentrated in specific patterns rather than spread diffusely, that it becomes worth investigating.

At our Delhi NCR clinic, we see patients across every age group, gender, and background asking this exact question — and the honest answer is that hair loss is rarely caused by just one factor. Genetics, hormones, nutrition, stress, medical conditions, medications, and even everyday hair care habits can all play a role, sometimes in combination. Identifying the actual cause — or causes — in your specific case is the single most important step toward effective treatment.

This comprehensive guide walks through the 15 most common causes of hair loss we encounter clinically, how to recognise which one might apply to you, and the evidence-based treatment options available for each.

 

Quick Facts Before We Begin •        Losing 50-100 hairs per day is normal — concern arises when shedding significantly exceeds this or follows a clear pattern •        Genetics (androgenetic alopecia) is the single most common cause of hair loss in both men and women •        Many causes of hair loss are temporary and fully reversible once the underlying trigger is addressed •        A proper diagnosis — not guesswork — is the foundation of effective treatment •        Early intervention consistently produces better outcomes than waiting, particularly for progressive causes

 

 

2. 15 Common Causes of Hair Loss — Complete Breakdown

Here is a detailed look at the fifteen causes our physicians most frequently identify during patient consultations, grouped logically for clarity.

 

1. Androgenetic Alopecia (Genetic Pattern Hair Loss)

The most common cause of hair loss worldwide, affecting an estimated 50% of men and up to 40% of women by age 50. Driven by genetic sensitivity to dihydrotestosterone (DHT), which gradually shrinks hair follicles over successive growth cycles. In men, this typically presents as a receding hairline and crown thinning; in women, as diffuse thinning at the crown with a widening parting.

 

2. Telogen Effluvium (Stress-Related Shedding)

A temporary condition where a significant proportion of hair follicles are pushed into the resting phase simultaneously, usually triggered by major physical or emotional stress — illness, surgery, childbirth, significant weight loss, or psychological stress. Shedding typically becomes noticeable 2-3 months after the triggering event and is usually diffuse across the whole scalp.

 

3. Thyroid Dysfunction

Both an underactive thyroid (hypothyroidism) and an overactive thyroid (hyperthyroidism) disrupt the hormonal signalling that regulates the hair growth cycle, leading to diffuse shedding. Often accompanied by other symptoms including fatigue, weight changes, and temperature sensitivity. A simple blood test (TSH, T3, T4) confirms or rules out this cause.

 

4. Iron Deficiency and Anaemia

Iron is essential for the cellular activity that drives hair follicle growth. Low serum ferritin — even without full-blown anaemia — has been repeatedly linked to increased hair shedding, particularly in women with heavy menstrual cycles or restrictive diets. This is one of the most under-diagnosed and most easily correctable causes we see clinically.

 

5. PCOS (Polycystic Ovary Syndrome)

Affecting up to 10% of women of reproductive age, PCOS involves elevated androgen levels and insulin resistance, both of which can drive pattern hair thinning similar to androgenetic alopecia. Often accompanied by irregular periods, acne, and excess facial or body hair — addressing the syndrome holistically improves outcomes beyond hair alone.

 

6. Postpartum Hormonal Shift

After childbirth, the sharp drop in estrogen following the high levels maintained throughout pregnancy causes a large proportion of hair follicles to enter the shedding phase simultaneously. This typically peaks 2-4 months postpartum and resolves naturally within 6-12 months for most women without intervention.

 

7. Menopause

As estrogen and progesterone decline during perimenopause and menopause, androgens become relatively more dominant, often accelerating pattern hair thinning that may have been present in a milder form for years beforehand. Read our detailed guide on hair loss after menopause for an in-depth look at this specific cause.

 

8. Alopecia Areata (Autoimmune Hair Loss)

An autoimmune condition where the immune system mistakenly attacks hair follicles, causing sudden, well-defined patches of hair loss — distinct from the diffuse or patterned thinning seen in most other causes. Requires dermatological diagnosis and a different treatment approach, often involving corticosteroid therapy.

 

9. Scalp Infections (Fungal and Bacterial)

Conditions such as tinea capitis (fungal scalp infection) or folliculitis (bacterial infection of hair follicles) cause inflammation that disrupts healthy hair growth and can lead to localised or generalised shedding. Often accompanied by itching, redness, flaking, or visible lesions on the scalp — these become notably more common during humid seasons.

 

10. Nutritional Deficiencies (Protein, Zinc, Vitamin D, Biotin)

Beyond iron, deficiencies in protein, zinc, vitamin D, and B-vitamins including biotin are well-documented contributors to hair thinning. Crash diets, restrictive eating patterns, and certain medical conditions affecting nutrient absorption all increase this risk. Blood-test-guided correction is far more effective than generic supplementation.

 

11. Certain Medications

A range of medications list hair loss as a potential side effect, including some blood thinners, antidepressants, beta-blockers, retinoids, and chemotherapy drugs. If hair loss began shortly after starting a new medication, this connection is worth discussing with both your prescribing doctor and a hair specialist — never stop a prescribed medication without medical guidance.

 

12. Traction Alopecia (Hairstyle-Related)

Caused by chronic, repeated tension on hair follicles from tight hairstyles — ponytails, braids, buns, or hair extensions worn consistently over months or years. Most commonly affects the hairline and temples. Caught early, traction alopecia is reversible by changing hairstyle habits; prolonged tension can cause permanent follicle damage.

 

13. Chronic Stress and Cortisol Elevation

Beyond triggering acute telogen effluvium, sustained chronic stress keeps cortisol levels elevated over long periods, which can continuously disrupt the hair growth cycle rather than causing a single shedding event. This often compounds with other causes on this list, making stress management a meaningful component of any treatment plan.

 

14. Excessive Heat Styling and Chemical Treatments

Frequent use of heat styling tools, chemical relaxers, perms, and harsh hair colouring treatments can weaken the hair shaft and damage follicles over time, leading to breakage that is sometimes mistaken for true hair loss. While this typically causes breakage rather than follicle-level shedding, severe or prolonged damage can affect the follicle itself.

 

15. Underlying Chronic Illness

Conditions including diabetes, lupus, and other chronic systemic illnesses can affect hair growth as part of their broader impact on the body. Hair loss accompanying unexplained fatigue, joint pain, skin changes, or other systemic symptoms warrants a comprehensive medical evaluation, not just a hair-focused assessment.