What Damages Hair the Most?

WrittenbyDr. Edna Skopljak, M.D.
Last updated

Our hair is an integral part of our appearance, and maintaining its health and beauty is a constant pursuit. However, various factors can contribute to hair damage, leaving it dull, brittle, and prone to breakage. Understanding the most common culprits behind hair damage is crucial in developing an effective strategy to protect and revive your locks.

What damages hair the most?

While several factors can contribute to hair damage, excessive heat styling, chemical treatments, and environmental stressors are among the most damaging culprits. These factors can strip away the hair's natural protective layers, weaken its structure, and lead to dryness, breakage, and an overall compromised appearance.

Heat Styling Tools

One of the primary sources of hair damage is the excessive use of heat styling tools, such as blow dryers, flat irons, and curling wands. These tools expose your hair to high temperatures, which can cause the following issues:

  • Dehydration: Heat styling can cause the hair to lose moisture, leading to dryness, brittleness, and an increased risk of breakage.
  • Cuticle Damage: The cuticle is the outermost layer of the hair strand that protects the inner cortex. Excessive heat can cause the cuticle to lift and become rough, resulting in dull, frizzy, and damaged hair.
  • Protein Loss: High temperatures can cause the hair's internal protein structure to denature, leading to weakened strands and an increased risk of split ends and breakage.

Chemical Treatments

Chemical treatments, such as coloring, bleaching, perming, and straightening, are another significant source of hair damage. These treatments involve the use of harsh chemicals that can disrupt the hair's natural structure and protective barriers, leading to the following issues:

  • Cuticle Damage: Chemical treatments can cause the cuticle layer to become raised and roughened, making the hair more susceptible to moisture loss and breakage.
  • Disulfide Bond Disruption: The chemicals used in these treatments can break down the disulfide bonds that hold the hair's protein structure together, leading to weakened strands and increased brittleness.
  • Porosity Issues: Chemical treatments can make the hair more porous, meaning it can absorb and lose moisture more easily, leading to dryness and an increased risk of breakage.

Environmental Stressors

Environmental factors, such as sun exposure, pollution, and chlorine from swimming pools, can also contribute significantly to hair damage. These stressors can cause the following issues:

  • UV Damage: Prolonged exposure to the sun's UV rays can break down the hair's natural pigments and proteins, leading to discoloration, dryness, and brittleness.
  • Oxidative Stress: Environmental pollutants, such as smog and cigarette smoke, can generate free radicals that contribute to oxidative stress, which can weaken and damage hair strands.
  • Chlorine and Salt Water: Chlorine from swimming pools and salt water from the ocean can strip away the hair's natural oils and cause dryness, roughness, and an increased risk of breakage.

Additional Contributing Factors

While heat styling, chemical treatments, and environmental stressors are among the most damaging factors, other factors can also contribute to hair damage, including:

  • Improper Hair Care: Using the wrong hair products, not following a proper hair care routine, or neglecting to use protective measures (e.g., heat protectants, leave-in conditioners) can exacerbate hair damage.
  • Nutritional Deficiencies: A diet lacking in essential nutrients, such as proteins, vitamins, and minerals, can lead to weakened hair strands and an increased risk of breakage.
  • Hormonal Changes: Hormonal fluctuations, such as those during pregnancy or menopause, can affect the hair's growth cycle and lead to temporary hair thinning or shedding.

To minimize hair damage and maintain healthy, beautiful locks, it's essential to be mindful of these damaging factors and take preventive measures. This includes limiting heat styling, using protective products, avoiding harsh chemical treatments, protecting your hair from environmental stressors, maintaining a balanced diet, and following a proper hair care routine tailored to your hair's specific needs.

Is damaged hair leaving you stressed?

Scandinavian Biolabs Hair Strength Shampoo can help! This gentle, nature-inspired formula is designed to help repair your damaged hair:

  • Revitalize dry, brittle hair.
  • Reduce frizz and split ends.
  • Support stronger and healthier hair growth.
  • Cleanse without stripping natural oils.

Experience the difference of healthy, vibrant hair.

Hair Strength Shampoo | For Men
Hair Strength Shampoo | For Men
Gently removes excess oil for a balanced scalp
Hair Strength Shampoo | For Women
Hair Strength Shampoo | For Women
Gently removes excess oil for a balanced scalp

Read more:


Why you can trust Scandinavian Biolabs?

As your leading source for hair health information over the past 4 years, we never compromise on accuracy. When it comes to your health, you deserve information you can truly rely on - and earning your trust is our top priority.

Here's how Scandinavian Biolabs ensures every piece of content meets the highest standards of accuracy and integrity:

  • Credentialed Experts: Our reviewers are actively practicing doctors and medical researchers
  • Stringent Reviews: Content undergoes rigorous editing by subject specialists and review by a practicing doctor.
  • Evidence-Based: We rely on well-established research from trusted scientific sources like peer-reviewed journals and health authorities.
  • Full Transparency: Our editorial standards, writer credentials, reviewer credentials, correction process, and funding are all publicly documented.
  • Independent Voice: While we do promote products, we operate in a vacuum to business operations. Our main goal is just an unwavering commitment to providing medically-sound guidance.

You can count on Scandinavian Biolabs to consistently deliver the trustworthy health information you deserve. Read our Editorial Standards.

TrichoAI Hair Loss Analysis
Our free, anonymous and dermatologist-developed AI analyzes your hair loss in 30 seconds, suggesting personalized solutions to combat thinning. Understanding your hair condition has never been easier.
Yes, I want to fix hair loss

Dr. Edna Skopljak, M.D.

About the Writer

Edna Skopljak, MDUniversity of Ljubljana, Faculty of Medicine

Edna Skopljak, MD is a clinical doctor at the University Medical Center Ljubljana and a PhD candidate in Biomedicine at the University of Ljubljana. She combines clinical work with research and medical editing, bringing a clear, evidence-based lens to patient education. Previously, she held roles in the pharmaceutical sector (product management and chief medical officer) and served as a medical production editor for the journal Biomolecules and Biomedicine.

Dr. Skopljak’s publications span clinical topics, including urology and orthopedics. She has co-authored work affiliated with the Department of Orthopedic Surgery at University Medical Centre Ljubljana. She trained in medicine with early clinical experience in Slovenia, reflecting a long-standing focus on practical, patient-facing care.

She strictly follows our Editorial Standards: All medical statements are grounded in authoritative guidelines, FDA labels, and peer-reviewed studies, with clear distinction between approved treatments and adjunctive options.