Hair loss, or alopecia, is often dismissed as cosmetic. Yet it frequently signals **underlying metabolic or endocrine dysfunction**. Among individuals in their **30s and 40s**, particularly women, hair thinning may be attributed to a range of **internal factors** rather than topical issues.
This article outlines **five primary physiological contributors** to hair loss, emphasizing how these factors interconnect and what interventions may help reverse the process.
1. Androgenic Influence – DHT Sensitivity and Follicular Miniaturization
The most common cause of progressive hair loss is **androgenetic alopecia**, driven by **DHT (dihydrotestosterone)**—a byproduct of testosterone. DHT binds to androgen receptors in scalp follicles, leading to **miniaturization** and reduced anagen (growth) phase duration.
- 5α-reductase inhibitors like **finasteride** and **saw palmetto** are commonly used for DHT modulation.
- DHT impact is greater in genetically predisposed individuals.
2. Insulin Resistance and Hyperandrogenism
Emerging research connects **metabolic syndrome** to hair loss through **insulin resistance**, which increases circulating insulin and stimulates ovarian or adrenal **androgen production**.
- This mechanism is frequently observed in **PCOS (Polycystic Ovary Syndrome)** patients.
- Intervention through **low-GI diets**, **exercise**, and **metformin** has been shown to reduce androgenic symptoms.
3. Hypothyroidism and Thyrotoxic Hair Loss
Both **hypothyroidism and hyperthyroidism** can disrupt the normal hair cycle, especially the transition between the **anagen and telogen phases**. Hair becomes dry, sparse, and brittle, and often sheds diffusely.
- TSH and free T4 levels should be evaluated in persistent hair loss cases.
- Restoring **euthyroid status** often reverses hair shedding.
4. Telogen Effluvium Due to Psychological and Physiological Stress
Stress-related shedding is known as **telogen effluvium**, where a significant number of follicles enter the resting phase prematurely. This is often triggered by illness, postpartum changes, emotional trauma, or drastic weight loss.
- Symptoms appear 2–3 months post-event and often resolve within 6–9 months.
- Stress management, adaptogens, and adequate protein intake are vital.
5. Nutritional Deficiencies – Iron, Zinc, and Biotin
Micronutrient deficiencies are a reversible but frequently overlooked cause of hair loss. **Ferritin**, the iron storage protein, is especially crucial for hair follicle function.
- Low ferritin (< 30 ng/mL) is strongly associated with chronic telogen effluvium.
- Zinc, biotin, and vitamin D also support keratin production and follicular integrity.