What are the causes of alopecia (hair loss)?

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From the Guidelines

Hair loss is primarily caused by a combination of genetic, hormonal, and environmental factors, with androgenetic alopecia being the most common cause, and can be effectively managed with treatments such as topical minoxidil, oral finasteride, and addressing underlying nutritional deficiencies, as supported by recent studies 1.

Causes of Hair Loss

The causes of hair loss are multifaceted and can include:

  • Genetics: Androgenetic alopecia (male or female pattern baldness) is hereditary and involves the hormone dihydrotestosterone (DHT) shrinking hair follicles.
  • Hormonal changes: Thyroid disorders, hormonal imbalances, and menopause can lead to hair loss.
  • Medical conditions: Autoimmune conditions like alopecia areata, stress-related telogen effluvium, and skin conditions such as psoriasis and eczema can cause hair loss.
  • Medications: Certain medications, including chemotherapy drugs, blood thinners, and some antidepressants, can lead to hair loss.
  • Lifestyle factors: Poor nutrition, physical trauma to the hair, and excessive styling can contribute to hair loss.

Nutritional Deficiencies and Hair Loss

Recent studies have highlighted the importance of micronutrients in hair growth, with deficiencies in vitamins D, zinc, and folate being associated with alopecia areata 1. While the current evidence is largely based on small case-control studies and case reports, it suggests that maintaining adequate levels of these micronutrients may be beneficial for hair growth.

Treatment Options

Treatment for hair loss depends on the underlying cause and may include:

  • Topical minoxidil (Rogaine) for promoting hair growth and slowing down hair loss.
  • Oral finasteride (Propecia) for men with androgenetic alopecia.
  • Anti-inflammatory medications for autoimmune conditions like alopecia areata.
  • Hormone therapy for hormonal imbalances.
  • Addressing underlying nutritional deficiencies, such as supplementing with vitamins D, zinc, and folate, as supported by recent research 1. Intralesional corticosteroids, such as triamcinolone acetonide, can also be effective in stimulating hair regrowth, particularly in cases of alopecia areata, as shown in a study published in the British Journal of Dermatology 1.

From the Research

Causes of Hair Loss

  • Androgenetic alopecia (AGA) is the most common cause of hair loss, often challenging to treat 2, 3, 4, 5
  • Other causes of hair loss include:
    • Telogen effluvium: a nonscarring, noninflammatory alopecia of relatively sudden onset caused by physiologic or emotional stress 4
    • Trichotillomania: an impulse-control disorder; treatment is aimed at controlling the underlying psychiatric condition 4
    • Trichorrhexis nodosa: occurs when hairs break secondary to trauma and is often a result of hair styling or overuse of hair products 4
    • Anagen effluvium: the abnormal diffuse loss of hair during the growth phase caused by an event that impairs the mitotic activity of the hair follicle, most commonly chemotherapy 4
    • Genetic factors or predisposition 5, 6
    • Vitamin and mineral deficiencies 6
    • Skin problems, hair growth disorders, poor diet, hormonal problems, certain internal diseases, drug use, stress and depression, cosmetic factors, childbirth, and the chemotherapy process 6

Factors Contributing to Hair Loss

  • Genetic factors: individual diversity of causal agents, as well as of the sequence of events, or combined factors, must be kept in mind 5
  • Androgens: play a crucial role in the development of androgenetic alopecia 2, 5
  • Prostaglandins and epigenetic factors: also contribute to the development of pattern hair loss 5
  • Nutrition: the Mediterranean diet, rich in antioxidant, anti-inflammatory components, may play a role in hair loss treatment 6
  • Microbiomata, oxidative stress, and microinflammation: additional pathogenic factors that are suspected to contribute to pattern hair loss 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Treatment of Androgenetic Alopecia: Current Guidance and Unmet Needs.

Clinical, cosmetic and investigational dermatology, 2023

Research

Hair Loss: Common Causes and Treatment.

American family physician, 2017

Research

Understanding Pattern Hair Loss-Hair Biology Impacted by Genes, Androgens, Prostaglandins and Epigenetic Factors.

Indian journal of plastic surgery : official publication of the Association of Plastic Surgeons of India, 2021

Research

An overview of the genetic aspects of hair loss and its connection with nutrition.

Journal of preventive medicine and hygiene, 2022

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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