What can cause hair loss?

Hair loss doesn’t happen without reason, so what are the causes of hair loss?

Updated: Thursday 15 April 2021


hair loss causes

Hair loss is very common and it affects around 6.5 million men in the UK and around one in three women will suffer from hair loss or reduced hair at one point in their lives. Normally, we lose around 50-100 hairs a day, without even noticing. When hairs fall out and are not replaced, or is replaced with thinner hair, then it usually means you have started balding. Hair loss is normal and it is nothing to worry about, but it can be extremely frustrating and disheartening.

However, hair loss doesn’t happen without reason, so what are the causes of hair loss?

causes of hair loss
  • Heritage
    Male pattern baldness (formally known as Androgenic Alopecia) does mostly occur due to genetics, and usually from your maternal side, but more recent studies do suggest that hair loss can occur from both sides. Hair loss is determined by dihydrotestosterone (DHT) and how sensitive your hair follicles are. The androgen receptor (AR) interacts with DHT and testosterone and if the receptors are sensitive, this causes hair loss in men. The AR is usually found on the X chromosome, which is what led to the belief that hair loss occurs from the maternal side.
  • Age
    There are three phases in the hair cycle – growth, transition and the resting phase. Hair growth occurs in the growth phase, falls out during the transition and falls out in the resting phase. As we age, each hair strand spends more time in the resting phase which means that our hair fall out is greater than the amount of hair growing. Signs of baldness and a thinning scalp may be found on men by the time they are 30, with around 80% of men experiencing hair loss by the time they are 80 years old. Hair loss in men may be found around the temples, and scalp. Similarly, women develop female pattern baldness as they age, where the hair follicles begin to shrink, hairs become less dense and occasionally the scalp will become visible. As we get older, our hair also ages and especially when women reach their menopause phase, the hormonal changes in the body may impact your hair as well.
  • Poor Diet
    Hair loss can occur from a deficiency in certain nutrients, so your diet hugely impacts your hair growth. Your hair cells need the right balance of carbohydrates, protein, iron and vitamins and minerals is vital for optimum hair growth. Vitamin A is an essential nutrient for hair growth. Hair loss treatments contain Vitamin A, and diets containing it stimulates hair repair, and helps to prevent a dry scalp. However, excess Vitamin A in your diet will have the opposite effect, as your hair follicles will be unable to replace the hairs because it has reached their growth phase too quickly. The recommended amount is 0.7mg a day for men, and 0.6mg a day for women.
  • Stress
    Stress can trigger hair loss as well as other scalp conditions such as dandruff. In both men and women, stress increases the production of adrenalin, and has the capability of increasing the androgen levels in the body. When this occurs, this has huge implications on your hair growth, causing to lessen and fall out more leading to hair loss. During stressful period of time, our bodies responds to the stress by the release of hormones to prepare our body for what is known as the ‘fight or flight response’. The change in hormone levels can cause hairs to fall out.
  • Smoking
    There is some evidence to suggest that smoking and hair loss are linked. The way you can tell this is by location of your hair loss. Smoking has been linked to Telogen Effluvium, which is sudden or severe stress which can cause hair loss. This is temporary but the hair loss can be found all over the scalp and it can be treatment with treatment to help speed by the hair growth process. Although there is not clear evidence to suggest that smoking and hair loss are linked, it is believed that smoking cuts off the oxygen to the scalp which damages the DNA of hair follicles.
  • Depression
    Depression can cause you to feel in a low or bad mood, have low self-esteem and feeling physically and mentally drained. These are contributing factors of hair loss and can cause the hairs to become dry and break easier. Additionally, one of the side effects of some some anti-depressant medications is an increased hair loss rate.
treating hair loss

Okay so we’ve identified the causes of hair loss, but here’s how you can deal with it.

  • Medication
    There are two clinically approved medications that helps to prevent further hair loss – Finasteride and Minoxidil. Finasteride works by reducing the level of DHT, and effectively the Finasteride halts the hair loss process stimulating hair growth on the head. Minoxidil on the other hand, works by increasing the blood supply to the hair follicles. This helps to strengthen the existing hair and stimulate hair growth and prevent further hair loss. Regaine Extra Strength Solution and Regaine Extra Strength Foam are two products containing Minoxidil.
  • Take supplements
    Supplements containing a variety of vitamins and minerals to help stimulate hair growth is essential – especially Biotin. Hair products such as shampoo, conditioner and some hair oils containing Biotin are thought to stimulate hair growth and increase fullness on the head. More specifically, Viviscal and Nutrafol vitamins are also thought to promote hair growth.
  • Avoid hot showers
    Although there is no evidence suggesting that hot showers and hair loss are linked, hot showers can cause your scalp to dry out which eventually can cause your hair follicles to minimise and thin the hair.
  • Cut the bad habits
    Quitting smoking will not help with your hair loss, but it will do wonders for your overall health.
  • Cut down on hair styling
    Try to limit the use of hair dryers, straighteners and other hair tools. The high heat can damage your hair, making it more prone to fall out.
  • Hair Transplant
    Surgical procedures such as hair transplants can help to reduce hair loss. It works by taking hairs from your scalp which has plenty of hair, and implanting it into the affected areas, giving the appearance of fuller hair. This is costly, and it usually takes between 3-9 months to see the results.
Toby Watson

Written by: Toby Watson

Pharmica Medical Writer

Toby (BSc) is an experienced medical writer, producing educational articles on many areas of health including sexual health, fitness, nutrition and mental health.

He particularly enjoys debunking misconceptions around heath conditions and their treatments, researching each topic in detail and writing easily-accessible content.


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Hair Loss - What are my options?
Hair Loss - What are my options?