6 surprising causes of hair loss

Hair loss can be extremely frustrating, but the causes of hair loss may surprise you. We look at six causes of hair loss in men and women.

Although annoying, hair loss is a normal part of life. On average, we have around 100,000 hair follicles on our heads. And as part of our hair’s natural growth cycle, we lose around 100 hairs per day [1].  

However, some people lose more hair than others, and it can be difficult to discuss with friends and family, or even medical professionals. 

In this blog, we discuss:

Does age affect hair loss?

As we age, our hair follicles become less productive, resulting in a change in the colour and thickness of our hair [2]. However, age isn’t the only reason for hair loss.  

Our genetic makeup can also play a big role in the likelihood of developing hair loss -and hereditary-pattern baldness is the most common cause [3]. 

Although age and genetics are big factors in the causes of hair loss, there are several others that can contribute — some of which may surprise you. 

Can a hormone imbalance affect hair loss?

An imbalance in specific hormones can lead to hair loss in both men and women. 

For men, it is usually high levels of testosterone and dihydrotestosterone (DHT) that are the culprit for losing that head of hair.  

male hormone blood test product banner

In women, however, several hormonal changes can be the reason for losing those wavy locks. 

Hormone changes that can cause hair loss in women include [4]: 

  • Polycystic ovary syndrome (PCOS) — a common condition that affects the way the ovaries work. PCOS can increase the amount of body hair produced but can also decrease the amount of hair on the scalp.  
  • Postpartum — many women experience thinning hair or hair loss due to an imbalance in oestrogen levels after giving birth.  
  • Menopause — as menopause causes many hormonal changes, many women experience thinning hair or hair loss.   

Our Hair Loss Blood Test helps to investigate the possible causes of thinning hair and hair loss. It includes tests for key male hormones, including testosterone, SHBG, thyroid health, and iron status.  

If you’re wondering whether a female hormone imbalance could be causing your hair loss, then it’s worth looking at our Female Hormone Blood Test, which measures female and thyroid hormones.  


Can stress affect hair loss?

Stress can affect our health in several ways. Predominantly, stress has been linked with an increased risk of developing heart disease and diabetes. However, long-term stress (also known as chronic stress), or trauma to the body, can cause symptoms such as telogen effluvium (hair shedding) [5]. 

Hair shedding is generally temporary as the stress on the body causes the hair follicles to prematurely stop growing and shed the hair. So, the good news here is that it’s usually reversible — if you can control your stress levels. 

If you think stress could be causing symptoms such as hair loss, our Stress Cortisol Saliva Tests (4) can help you out. And if you are looking for ways to de-stress, give our 10 top ways to de-stress blog a read.

Do autoimmune diseases cause hair loss?

An autoimmune disease occurs when the immune system attacks healthy cells in the body, mistaking them as harmful. When the body attacks healthy hair follicles, this can cause hair loss.  

Autoimmune disorders that can cause hair loss include [6]: 

  • Thyroid condition — hormones T4 and TSH are important in determining whether an underlying thyroid condition is to blame for a sudden loss in hair.  
  • Alopecia areata — the most common autoimmune condition associated with hair loss.  
  • Lupus - causes inflammation on the scalp, which can eventually lead to thinning hair. 
  • Crohn’s disease — Crohn’s has been linked with alopecia areata, but also can cause malabsorption, meaning that the body may result in a mineral deficiency [7]. 

If you have an autoimmune disorder, then you may already be aware of hair loss as a symptom. However, getting an Antinuclear Antibodies (ANA) Blood Test can help to identify the presence of an autoimmune disease.  

Inflammation markers can help determine whether there is inflammation in the body that could be caused by an autoimmune disease. Inflammatory markers and thyroid hormone biomarkers are both included in our Hair Loss Blood Test

Can low iron levels cause hair loss?

Iron is required in the body to produce haemoglobin — a protein vital for carrying oxygen around in the blood. Hair follicles require haemoglobin to grow and remain healthy [8], so when the body is deficient in iron, this often results in slow hair growth and hair loss.  

Within the body, iron is stored as ferritin. Low ferritin is often the first detectable marker of iron deficiency. For this reason, ferritin levels are included as part of our Hair Loss Blood Test too. ​ 

iron blood test product banner

Can a mineral deficiency cause hair loss?

We get minerals from the foods we eat, and they are essential for the body to effectively carry out daily functions and processes.  

Minerals that are essential for daily bodily functions include: 

  • Selenium — a micronutrient that is essential in hair growth. However, it should be noted that high doses of selenium can be toxic and have been reported to do the opposite and cause alopecia [9]. 
  • Zinc — a vital mineral for the health of the hair follicles and the hair's growth cycle. A lack of zinc is a common cause for hair loss [10].  
  • Magnesium — plays an important role in the growth of hair by helping the body to absorb calcium. 

Other vitamins and minerals such as vitamin C, vitamin D, and biotin may play a part in hair loss. But, like many of these minerals and vitamins, the evidence for nutrition and hair health can be contradictory due to the lack of robust research. 

If you think that a mineral deficiency may be to blame, you can check your iron, magnesium, and zinc levels with one of our tests. 

Can overstyling your hair cause hair loss?

Although styling our hair may help us achieve what looks like beautiful, healthy hair, excessive use of hair dyes, hair dryers, straighteners, and curlers can lead to weak, brittle hair that may fall out more easily.  

To help keep your hair healthy, instead try: 

  • Going a little easier on the styling products 
  • Letting your hair air dry 
  • Using leave-in conditioners can all help to improve the strength of your hair 
  • The Curly Girl Method (trading damaging habits for healthy hair) 

Also check your shampoos for any silicones or chemicals and look at switching to paraben-free hair care – these unnatural oils can affect the hair’s growth cycle, and lead to weak and damaged hair, ultimately leading to hair loss. 

What’s causing my hair loss?

Though hair loss can be frustrating, it might be your body’s way of showing you something is wrong. Finding the source of the problem may mean you can reverse the effects with a few lifestyle changes.  

There are reasons other than these six that can cause hair loss, and if you are experiencing it alongside other symptoms, we recommend you speak to your GP.  


  1. Murphrey MB, Agarwal S, Zito PM. Anatomy, Hair. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available at: <https://www.ncbi.nlm.nih.gov/books/NBK513312/> [Accessed 11 February 2022] 
  2. Trueb, R., Rezende, H. and Dias, M., 2018. A comment on the science of hair aging. International Journal of Trichology, 10(6), p.245. 
  3. Harvard Health. 2022. Hereditary-Patterned Baldness - Harvard Health. [online] Available at: <https://www.health.harvard.edu/a_to_z/hereditary-patterned-baldness-a-to-z#:~:text=Hereditary%2Dpattern%20baldness%20is%20the,hair%20thinning%20as%20they%20age. [Accessed 11 February 2022]. 
  4. Grymowicz, M., Rudnicka, E., Podfigurna, A., Napierala, P., Smolarczyk, R., Smolarczyk, K. and Meczekalski, B., 2020. Hormonal Effects on Hair Follicles. International Journal of Molecular Sciences, 21(15), p.5342. 
  5. Malkud, S., 2015. Telogen Effluvium: A Review. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH,
  6. Robotic Hair Solutions. 2022. Autoimmune Disorders and Your Hair Loss. [online] Available at: <https://rhrli.com/blog/autoimmune-disease-cause-hair-loss/> [Accessed 11 February 2022]. 
  7. Relief, I., 2022. Hair loss and IBD | IBDrelief. [online] IBDrelief. Available at: <https://www.ibdrelief.com/learn/complications-of-ibd/hair-loss-and-inflammatory-bowel-disease-ibd> [Accessed 11 February 2022]. 
  8. Guo, E. and Katta, R., 2017. Diet and hair loss: effects of nutrient deficiency and supplement use. Dermatology Practical & Conceptual, pp.1-10. 
  9. Senthilkumaran, S., Balamurugan, N., Vohra, R. and Thirumalaikolundusubramanian, P., 2012. Paradise Nut Paradox: Alopecia Due to Selenosis from a Nutritional Therapy. International Journal of Trichology, 4(4), p.283. 
  10. Almohanna, H., Ahmed, A., Tsatalis, J. and Tosti, A., 2018. The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatology and Therapy, 9(1), pp.51-70. 

Related tests

Hair Loss Blood Test

Investigate possible causes of hair thinning or loss including a hormone imbalance, thyroid problems, vitamin D deficiency, and low iron, with our home blood test

  • Results estimated in 7 working days
  • 7 biomarkers
Cortisol Saliva Stress Test

Our popular cortisol saliva test helps you understand your stress levels and adrenal function by testing your cortisol levels 4 times over the course of a day

  • Results estimated in 3 working days