View Full Version : Different causes of Hair loss

02-24-2015, 03:23 AM
Causes of hair loss

The medical term for hair loss is alopecia. There are several causes of hair loss, though the most likely cause for any man losing his hair is the genetic male pattern baldness (MPB) and the root cause behind MPB is your level of DHT (Dihydrotestosterone). Sooo many three letter acronyms! Women can also lose their hair through female pattern baldness but it is usually a very different pattern to men. Before we go into detail about MPB and DHT, we’ll briefly look at the other possible causes for thinning hair.

Defective hair shaft

There are a whole multitude of conditions where a defective hair shaft will cause loss of hair. In many cases it will be the fibre has not been properly formed inside the follicles thus resulting in hair shaft defects. Poor hair care and grooming can lead to hair shaft defects but you have to be pretty mean to your hair to cause problems through grooming.

Hair shaft defects may be the result of loose anagen syndrome which means the hair is loose in the hair shaft and is easily pulled out. You will notice this in newborn babies who are born with a head full of hair but lose it shortly after. When an infant lies on its back for long periods of time you will notice the hair on the back of the head becomes very thin. Most babies will outgrow this condition as they become toddlers.

People with blonde hair tend to have more hair shaft defects than those with darker coloured hair. Often it is considered to be hereditary because it tends to run in families. Fortunately the problem will usually get better with age and the hair shaft will become stronger.

Traction alopecia is also associated with hair shaft defects. This is usually caused by wearing tight hairstyles such as braided corn rows or pony tails which are pulled very tight. This is a condition that is easily corrected by letting the hair hang loose, but if the hair has constant strain on it there will be damage to the hair shaft over time. If the condition is allowed to continue long enough it will cause permanent hair shaft defects that will never grow hair. (This can be a problem where your religious beliefs dictate that you wear a turban all the time or braid your hair and beard permanently).

Trichotillomania is condition where an individual pulls on their hair and plucks it out in spots. This will leave bald patches on the head and if left untreated can cause a defective hair shaft that will no longer be able to grow hair. This condition is usually a psychological issue that needs professional assistance to address the underlying cause of the behaviour.
Some people will cause hair shaft defects by over processing their hair with perm solution or hair dyes. Generally if the perming and dying is performed by a professional hairdresser, this is not an issue.


Since the follicle is a very sensitive it does respond to imbalances in the body. Most hair loss caused by disease or illness is temporary and resolves itself after the body has returned to a normal healthy condition. It can happen that one to three months after a high fever, severe infection or flu, a person may experience hair loss; this is usually temporary and corrects itself.

Thyroid problems

Both an overactive thyroid and an underactive thyroid can cause hair loss. Hair loss associated with thyroid disease can be reversed with proper treatment.

Deficient diet

Some people who go on low protein diets, or have severely abnormal eating habits, may develop protein malnutrition. To help save protein the body shifts growing hair into the resting phase. If this happens, massive amounts of hair shedding can occur two to three months later. This condition can be reversed and prevented by eating the proper amount of protein.


Some prescription drugs may cause temporary hair shedding in a small percentage of people. Examples of such drugs include some of the medicines used for the following: gout, arthritis, depression, heart problems, high blood pressure, or blood thinning. High doses of vitamin A may also cause hair shedding.

Cancer treatments

Chemotherapy and radiation treatment will cause hair loss because it stops hair cells from dividing. Hairs become thin and break off as they exit the scalp. This occurs one to three weeks after the treatment. Patients can lose up to 90 percent of their scalp hair. The hair will grow back after treatment ends.

Iron deficiency

Iron deficiency occasionally produces hair loss. Some people don't have enough iron in their diets or may not fully absorb iron in their diets. Women who have heavy menstrual periods may develop iron deficiency. Low iron can be detected by laboratory tests and can be corrected by taking iron pills.

Major surgery/chronic illness

Anyone who has a major operation, which can be a tremendous shock to the system, may notice increased hair shedding within one to three months afterwards. The condition reverses itself within a few months but people who have a severe chronic illness may shed hair indefinitely.

Alopecia Areata

This type of hair loss is believed to be caused by the immune system reacting to hair follicles as if they were antibodies and shutting them down. The hair loss is usually limited to a small area leaving a totally smooth round patch. In a more severe rarer condition called Alopecia Totalis, all hair on the entire body is lost, including the eyelashes. Treatments include topical medications, a special kind of light treatment, or in some cases drugs.

Fungus Infection (Ringworm) of the scalp

Caused by a fungus infection, ringworm begins with small patches of scaling that can spread and result in broken hair, redness, swelling, and even oozing. This contagious disease is most common in children and oral medication will cure it.


Stress can cause hair loss is some people. Usually it occurs around three months after the stressful event has occurred and it may take some months after the stress period has ended for the hair growth to resume. In most cases it is temporary. If the person is predisposed to genetic or Androgenic Alopecia (another name for male pattern baldness) then the stress may trigger the onset of genetic hair loss or may worsen existing hair loss.


Sebum is produced by the sebaceous glands in the skin, and as we saw earlier in this chapter, it is an oily substance that is used to moisturise the skin preventing it from drying out keeping hair and skin conditioned and healthy. It also helps prevent the build up of certain bacteria. Basically sebum is vital for healthy hair and skin.
However, too much sebum is not good. If excess sebum is not washed out by shampooing, it can build up in the follicle. Eventually it makes its way to the top of the scalp and oxidises with the air. This causes the sebum to harden and bacteria thrive off this hardened sebum damaging the hair follicle. Eventually the blockage stops nutrients getting into the follicle making it practically impossible for hair to grow. This is called seborrheic alopecia, not to be confused with alopecia due to seborrheic dermatitis (an inflammation of the skin causing red itchy and flaky patches to occur).
Sebum can also cause high levels of the male hormone dihydrotestosterone (DHT) to occur, and, as we are about to see, DHT is very strongly linked with male baldness. It follows if you can keep sebum at healthy levels then your hair will have a much better chance.

The main thing to note is that many things can cause temporary hair loss and it will usually grow back once that particular problem is dealt with. Male pattern baldness however is not temporary, it is permanent especially if not detected early and left unchecked.

So let’s investigate male pattern baldness (MPB), and the DHT that causes it.


DHT is Dihydrotestosterone. It is produced by metabolism of the hormone testosterone and is formed in the adrenal gland, hair follicles, prostate glands and testes. DHT is a naturally occurring hormone, all men have it, but in genetically predisposed men, it can cause MPB. We need DHT for the formation of the male specific characteristics such as development of the body hair, development of the facial hair, depth of voice etc. However after puberty, an abundance of DHT is no longer needed. For most men an excess of DHT causes no problem. If, however, you are genetically predisposed to MPB, then it does.

The current theory is that DHT binds to the hair follicles, then enters cells preventing ribonucleic acid (RNA) polymerase from functioning, RNA is key to protein synthesis. In plain English, this means if hair cells cannot create protein then hair will not grow and eventually will die.

DHT occurs as the result of a metabolic process where an enzyme called 5-alpha-reductase (5AR) converts testosterone into DHT. Basically: Testosterone in hair follicles + 5AR = DHT = bad news! Studies confirm that men showing signs of baldness have increased activity of 5AR in their scalps. And an excess of sebum in the scalp can encourage the production of 5AR, which is why keeping sebum levels under control is vital. It follows therefore that if we can stop 5AR from working we can reduce DHT levels and prevent MPB from developing.

There are some contentious issues here as there are two types of 5AR, Type I and Type II. Nobody is 100% sure exactly how much each enzyme contributes to the DHT production that leads to baldness. The Type I enzyme is commonly found in the glands in the skin in close proximity to hair follicles, Type II is found in the dermal papillae of hair follicles, both types are found in other places around the body too.

There are products - DHT Blockers – which can inhibit production of DHT and hence reduce its capacity to damage the hair follicle. There are many topical DHT blockers and inhibitors that are easily available in the open market under different brand names, being manufactured and marketed by different companies. We will look at these in detail in the next chapter.

Drugs to block 5AR have been available for a while. Finasteride (sold as Propecia) blocks the type II 5AR reducing DHT levels by up to 60% to 70%. This has seen about one in three users grow new hair on the crown of their heads. A Type I 5AR blocker was tested and the results showed there was no hair re-growth in the patients who undertook the trial. It seems that the Type II enzyme which is located in the hair follicle is the main culprit. Another drug called Dutasteride (sold as Avodart) blocks both Type I and II. This drug was developed for men suffering with an enlarged prostate which is also caused by excess DHT.

So it’s simple, take a load of DHT blockers and Bob’s your Uncle, right? Not quite, you should be aware that the full functions of DHT are not completely understood, for example deficiency in DHT has been linked with a risk of Alzheimer’s disease and it plays important roles in the development of male characteristics such as muscle growth and keeping other hormones such as estrogen in check. The long term implications of blocking DHT are not fully known. Another significant factor to consider is once you start taking the drugs you will more than likely need to take them for the rest of your life if you want to keep your hair, which is far from ideal.

There is much to think about before you rush off and purchase one of the DHT blockers. And before you start taking any drug at all, you need to understand Male Pattern Baldness and its measurement the Norwood Scale, because the extent of your MPB will determine the combination of treatments that will work best for you.


Agustin Araujo
02-26-2015, 02:38 PM
Thank you for the post Spex. It was interesting to read many of the possible causes of alopecia.

02-26-2015, 09:01 PM
Awesome write-up. Thanks for posting

12-08-2015, 05:05 AM
Nice post. As given due to iron deficiency women may suffer from hair-loss, its better to consult with the doctor on time when heavy menstrual (http://www.cupissima.com) period persist during menstruation so that to avoid further complication.

01-26-2016, 07:34 PM
Causes of hair loss

This is called seborrheic alopecia, not to be confused with alopecia due to seborrheic dermatitis (an inflammation of the skin causing red itchy and flaky patches to occur).
Sebum can also cause high levels of the male hormone dihydrotestosterone (DHT) to occur, and, as we are about to see, DHT is very strongly linked with male baldness. It follows if you can keep sebum at healthy levels then your hair will have a much better chance.


I have Seborrheic Dermatitis Inflammation hair loss. When you say "not to be confused for" what do you mean? That inflammation hair loss caused by Seborrheic Dermatitis is in some way different? I am suffering from this. Will it grow back? My DHT levels were low my endo said.