Hair fall can be caused due to environmental pollutants or poor hair care routine. In some cases, it could be due to an underlying health problem. Whatever is the cause of the hair fall, knowing about it is important for getting the right treatment.
But before knowing about the common hair fall reasons, it is important to understand the hair growth cycle and whether your hair loss is temporary or permanent.
Hair growth cycle
Each hair follicle goes through three phases:
Anagen phase is the active phase of hair growth that usually lasts for about two to six years. Around 85-90% hair on the scalp is in this stage at a given point in time.
Catagen phase is the transitional phase that lasts few weeks (2-3 weeks). Only 1% hair is in this stage.
Telogen phase is the end phase of hair growth, which is the resting phase. Around 13% of our hair is in this stage.
At the end of the telogen phase, hair follicles shed, which is replaced by new hair and the cycle continues. However, the hair growth cycle can be influenced by an individual’s age, diseases, hair care routine, and diet.
Common reasons for hair fall and hair loss in men and women
1. Age: With age, there is a gradual decline in hair growth and an increase in hair fall. This could be due to the changes in the hormones and the weakened immune system. Moreover, as you age the hair follicles die and thus, there is more permanent hair loss.
2. Heredity (Genetic)*: Genes do play a key role in hair loss. Hereditary hair loss, commonly known as male-pattern baldness or female-pattern baldness, is one of the common reasons for hair fall in both men and women. It mostly occurs with age and the hair loss pattern is quite predictable. For example, hereditary hair loss causes bald spots and receding hairline in men whereas in women it causes hair thinning beginning from the parting.
3. Hairstyles: One of the common but preventable causes of hair loss in women is sporting tight hairstyles such as ponytails, bun or braids. When you pull the hair too tight it exerts pressure on the hair follicles that can damage the hair and cause permanent hair loss. Moreover, use of hair styling products and tools such as straighteners and hair dyes can rip off moisture and oil from the hair and make it dry, frizzy, which ultimately causes hair fall.
4. Shampoos: It is important to regularly wash your hair to maintain hair care but choosing the right shampoo is also important. Use of shampoos laden with chemicals on a regular basis can remove the protective layer of sebum (oil) from the hair strands. This causes the hair shaft to dry out and be more prone to friction leading to hair damage and hair fall. It is recommended to use mild shampoos.
5. Nutritional deficiencies: Nutritional deficiency can also lead to hair loss as it can impact the structure of the hair follicles and also hair growth. Studies have shown the link between nutritional deficiency and telogen effluvium, alopecia areata, androgenetic alopecia and female pattern baldness. Some of the common nutritional deficiencies that can cause hair loss include:
-Omega 3 fatty acids deficiency
-Vitamin E deficiency
-Vitamin A deficiency
-Vitamin D deficiency
-Folic acid deficiency
– Antioxidants deficiency
To know if your hair loss is caused due to lack of nutrients and whether supplements can help restore hair growth and prevent hair loss, you need to consult your dermatologist.
6. Weight loss: Sudden weight loss can also lead to hair loss. According to the American Academy of Dermatology, hair loss can happen after 3-4 months of losing more than 15 pounds (approx 7 kg) of weight. Although the exact mechanism is not known it can be due to lack of nutrients that are needed for hair growth. Several health conditions can also cause weight loss, which in turn can trigger hair loss. Telogen effluvium* and alopecia areata* are the common types of hair loss caused due to weight loss.
7. Crash diets: For most people crash diets are a simple and easy alternative to control diet and lose weight. However, what they are unaware of is the fact that crash diets fail to provide sufficient nutrition to the body, which in turn can affect the proper functioning of the body including the hair follicles. For example lack of proteins and antioxidants in diets such as cash diets can cause telogen effluvium, which can be prevented by ensuring a healthy and balanced diet.
8. Medications: Hair loss is one of the common side-effects of medications such as blood thinners and anti-hypertensive medications. Chemotherapy drugs used to treat cancer can also lead to hair loss. Medications such as birth control pills and hormonal pills to treat symptoms of menopause can also lead to temporary hair loss in women.
9. Chemotherapy and radiation: Chemotherapy and radiation therapy during cancer treatment can lead to hair loss.
10. Illness: You might have heard that post an illness, there is drastic hair fall. This is because conditions such as flu, high fever, anemia or even a major surgery causes stress which in turn impairs the normal functioning of the hair growth cycle, leading to hair loss. However, hair loss due to illness is temporary and can be treated by treating the underlying cause of the disease.
11. Scalp infections: Bacterial or fungal infections of the scalp such as ringworm or dandruff can lead to hair fall. If left untreated, ringworm infection of the scalp can lead to balding or permanent hair loss.
12. Stress: One of the major hair fall reasons that can be managed is stress. When stressed the body release cortisol, stress hormone and also impact the proper functioning of other hormones in the body. This causes a shift in the normal hair growth cycle which causes majority of the hair follicles to enter the telogen phase and lead to hair loss (telogen effluvium).
13. Trichotillomania: It is an an impulsive control disorder that can lead to hair loss. People suffering from trichotillomania have a recurrent and irresistible urge to pull out hair from scalp, eyebrows and other areas of the body. It is a psychological condition that needs help from a psychologist /psychiatrist.
14. Hormonal conditions: It is a known fact that changes in the hormonal level can have a significant impact on the body including the hair. Hormonal conditions that can lead to hair loss include:
In women, numerous changes occur during pregnancy and post delivery that can lead to hair loss. Also, in some women, post 40 or during menopause, it can lead to hair loss.
15. Eating disorders: Not just lack of nutrients and following crash diets, but people suffering from eating disorders can also experience hair loss. It is quite common in people with anorexia (not eating enough) and bulimia (vomiting after eating). Hair fall in these cases could be attributed to improper nutrient intake.
Whether you go to the doctor because you notice thinning or your braid is not as thick or you see more strands in your comb than usual, your dermatologist will examine the exact cause of hair fall and then diagnose the condition.
Here are the different types of hair loss*:
Alopecia is a medical term that refers to baldness and or hair loss. Hair loss over a part of the scalp or the entire scalp can be due to these conditions.
1. Androgenic/androgenetic alopecia: It is one of the most common types of hair loss that causes permanent hair loss from the scalp. As the name suggests it is a genetic condition that can affect both men and women.
-In men, it is known as male pattern baldness, which is characterized by gradual thinning and hair fall from the crown and front region and can occur at an young age (early 20s).
-In women, it is known as female pattern baldness, which causes thinning of the centre hair part. Unlike men, in women, it usually occurs at the age of 40 and above.
2. Alopecia areata: It causes sudden hair loss which is characterized by one or more circular bald patches on the scalp and hence, known as spot baldness. It could be an autoimmune disease (where the immune cells attack hair follicles) or may be due to stress. In some cases the hair regrows and it can be treated unless over half the hair is lost.
3. Alopecia totalis: It is a type of hair loss that causes baldness over the entire scalp (complete baldness). The exact cause is not known but it is believed to be the advanced form of alopecia areata.
4. Alopecia universalis: Unlike alopecia totalis, alopecia universalis causes hair loss not just from the scalp but all over the body. This includes hair loss from the eyebrows, underarms, and pubic region.
5. Traction alopecia: This condition is caused by pulling of the hair repeatedly while braiding, pony tailing or styling. Avoiding these grooming mistakes can help you to prevent this type of hair loss. If left ignored, it can lead to permanent hair loss.
6. Telogen effluvium: It causes temporary thinning of the hair and hair loss over the scalp, which can be fixed by treating the underlying cause of the condition. It occurs when a large number of hair follicles enter into the telogen phase causing hair fall, thinning of hair and hair loss, following a stressful event.
7. Anagen effluvium: In this condition, there is an abnormal loss of hair in the anagen phase caused due to chemotherapy or other drugs or exposure to toxic chemicals.
8. Cicatricial alopecia: Also known as scarring alopecia, it is characterized by inflammation of the hair follicle that form a scar on the scalp and destroys the hair follicles. As a result, it causes irreversible or permanent hair loss.
This article is reviewed by Dr. Anoop Purkayastha, Dermatologist.
Hair loss: Who Gets and Causes. American Academy of Dermatology. https://www.aad.org/public/diseases/hair-and-scalp-problems/hair-loss#causes
Gordon KA, Tosti A. Alopecia: evaluation and treatment. Clin Cosmet Investig Dermatol. 2011;4:101-6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3149477/
Monselise A, Cohen DE, Wanser R, Shapiro J. What ages hair? Int J Womens Dermatol. 2015 Oct 9;1(4):161-166. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5419772/
Guo EL, Katta R. Diet and hair loss: effects of nutrient deficiency and supplement use. Dermatol Pract Concept. 2017 Jan 31;7(1):1-10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5315033/
Malkud S. Telogen Effluvium: A Review. J Clin Diagn Res. 2015 Sep;9(9):WE01-3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4606321/
R.A. Hajare1, A.G.Tated. Onion juice: An effective home remedy for combating alopecia.IJPRD, 2013; Vol 4(11): (093 – 097).