What are the causes of alopecia (hair loss)?

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Last updated: March 14, 2025View editorial policy

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From the Guidelines

Alopecia, or hair loss, can be caused by a combination of genetic, hormonal, environmental, and nutritional factors, including autoimmune disorders like alopecia areata, where micronutrient deficiencies such as vitamin D, zinc, and folate may play a role 1. The causes of alopecia are multifaceted and can include:

  • Genetic factors, such as male or female pattern baldness, where hair follicles become sensitive to dihydrotestosterone (DHT)
  • Hormonal changes during pregnancy, menopause, or thyroid disorders
  • Medical conditions like alopecia areata, an autoimmune disorder, scalp infections, and skin disorders
  • Certain medications, including those for cancer, arthritis, depression, heart problems, and high blood pressure
  • Stress, whether physical or emotional, which can push hair follicles into a resting phase, resulting in shedding
  • Nutritional deficiencies, particularly of iron, protein, vitamin D, and zinc, which can weaken hair
  • Harsh hair treatments like tight hairstyles, excessive heat styling, and chemical treatments that can damage hair follicles and cause breakage According to the most recent guidelines, treatment for alopecia areata may include intralesional corticosteroid for limited patchy hair loss and contact immunotherapy for extensive patchy hair loss 1. It's essential to identify the specific cause of hair loss, which may require consulting a dermatologist for proper diagnosis and personalized recommendations, as the treatment approach can vary significantly depending on the underlying cause, and in some cases, not treating may be the best option due to the tendency for spontaneous remission and the lack of adverse effects on general health 1.

From the Research

Causes of Alopecia

The causes of alopecia, also known as hair loss, are multifaceted and can be attributed to various factors, including:

  • Genetic factors 2, 3, 4
  • Hormonal imbalances 3, 4
  • Environmental factors 2, 3
  • Lifestyle factors, such as diet and nutrition 2, 3
  • Oxidative stress, which can be mediated by the release of transforming growth factor-β (TGF-β) 2
  • Vitamin and mineral deficiencies 3
  • Skin problems and hair growth disorders 3
  • Poor diet 3
  • Certain internal diseases 3
  • Drug use 3
  • Stress and depression 3
  • Cosmetic factors 3
  • Childbirth and the chemotherapy process 3

Role of Nutrition

Nutrition plays a significant role in hair loss, with certain nutrients counteracting oxidative stress, repairing cellular damage, and supporting cellular functions to restore hair growth 2. The Mediterranean diet, rich in antioxidants and anti-inflammatory components, has been shown to be beneficial in the treatment of hair loss 3. However, it is essential to note that covert subclinical nutritional deficiencies are common, and higher doses of nutrients do not necessarily mean higher efficiency, as they may reverse the benefits and become prooxidant 2.

Androgenetic Alopecia

Androgenetic alopecia (AGA) is the most common cause of hair loss in men and women 5, 6. It is characterized by the progressive miniaturization of follicles, leading to a decrease in hair density and a non-scarring diffuse alopecia 4. The pathogenesis of AGA is influenced by genetic, hormonal, and environmental factors, and response to treatment is variable 4.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

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

Journal of preventive medicine and hygiene, 2022

Research

Female Pattern Hair Loss: a clinical and pathophysiological review.

Anais brasileiros de dermatologia, 2015

Research

Treatment of Androgenetic Alopecia: Current Guidance and Unmet Needs.

Clinical, cosmetic and investigational dermatology, 2023

Research

Physical Treatments and Therapies for Androgenetic Alopecia.

Journal of clinical medicine, 2024

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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