Diagnosing hair loss
Diagnosing hair loss


Whilst you may be sure your hair is thinning, a clinical definition of hair loss must be reached to determine if you are losing more hair than normal and if you have a particular type of hair loss condition that can be treated.  Hair loss can be caused by  prescription medication, some types of infection, weight loss or inflammatory diseases like Crohn’s disease.

Your doctor, trichologist or dermatologist must first take a detailed medical history to determine;

  • Family history of hair loss
  • Current or recent infections
  • Recent surgery
  • Prescribed medications that could be contributing to your hair loss condition
  • Autoimmune conditions that can affect hair growth
  • Whether you may have postpartum hair loss
  • Whether you potentially have a hormone imbalance
  • Whether you are in an unusually stressful point in your life
  • Whether you have a vitamin or mineral deficiency or
  • Whether you have a medical condition such as diabetes or thyroid disease

Once a medical history is taken, the clinical features of your hair loss must be taken into account.


Clinical features differ depending on the type of hair loss you are experiencing.  Hair loss can occur as hairless lesions on the scalp or as a receding hairline.  In some cases, there can be abrupt shedding that ceases but where new hair fails to regrow.  To determine the appropriate treatment for hair loss, there are four main evaluations that can be used to asses hair loss type and also to record progress.

The following tests can be used diagnose hair loss:

Hair pull test – This involves pulling a section of around 40-60 hair to establish how many are easily removed from the scalp.  If more than 10% of hair can be removed with a light tug this would be regarded as a positive result.  This would signal to the practitioner that a higher number of hairs than normal are in the ‘resting’ phase.  This type of test is normally used to diagnose telogen effluvium or diffuse hair loss.

Scalp biopsy – This procedure is usually carried out by a dermatologist and can identify high numbers of antibodies and white blood cells around the hair follicle.  This is useful for determining of hair loss is due to an autoimmune condition such as hair loss.  A scalp biopsy can identify abnormal bacteria within the follicle that can restrict hair growth.  Scalp biopsies are stern used to identify hair loss conditions such as alopecia areata and scarring alopecia.

Blood tests – Blood tests are often used to determine whether hair loss is due to a vitamin or mineral deficiency or due to an androgen/estrogen imbalance.  A blood test can also pick up thyroid disorders or other inflammatory conditions.  Blood tests are good for confirming a diagnosis of andrognic alopecia and can also direct potential treatment of diffuse hair loss by pin-pointing issues such as iron deficiency or low folate levels.  Whilst blood tests are helpful it is important they are correctly interpreted or your blood test results may be misleading.

Trichograms – A trichogram is a technique of evaluating how many hairs are in the growing phase and it can also determine differences in the width of hair follicles in different areas of your scalp.  This method of evaluation allows your practitioner to evaluate individual roots that are at different stages in the hair growth cycle.  This diagnostic method is good for diagnosing early stages of androgenic alopecia.

Examination with a dermascope – This simple examination can pick up ‘exclamation mark’  hairs that are characteristic in the early stages of alopecia areata.

Female hair loss

Savin scale – The Savin scale can be used to asses the severity of hair loss in androgenic alopecia.

Alopecia areata- The arrow points to a typical hairless lesion seen in patients with alopecia areata.


Diagnosing the cause of hair loss should be fairly simple by using 2 or more of these diagnostic techniques.  It can take a few weeks to complete a range of tests but usually the diagnosis will be definitive with a clear treatment plan.  More complicated types of hair loss or rare genetic hair loss conditions are best dealt with by a dermatologist that has specific experience with complex hair loss cases.

One particular study was able to come up with a clear algorithm to determine types of hair loss which is very useful for medical practitioners.

Often hair loss happens for a number of reasons and patience is needed when embarking on any type of hair loss treatment plan as the results can take at least 3 months to be evident.