Anyone looking for information about hair loss repeatedly comes across the words alopecia and effluvium. What do they mean?
These two terms resolve a certain ambiguity that is inherent in the colloquial use of the word hair loss. People who talk about hair loss either actually mean that he or she is losing more hair than usual. Or it is actually less about falling out than about missing hair.
Especially male androgenetic hair loss (the development of baldness and receding hairline) and its female counterpart are usually not accompanied by noticeably increased hair loss. In this case, the thinning of the hair is primarily caused by a gradual miniaturization of the hair follicles and the hair they produce over the course of several follicle cycles.
Alopecia is used, quite casually, in the sense of “less hair than normal”. The term says nothing about how the hair was lost. (So if the dermatologist diagnoses you with alopecia, he basically tells you nothing you do not already know: you have thinning hair). Alopecia is the hairless or hairless condition of the hairy scalp. Alopecia is common – and not always the result of increased hair loss. Conversely, increased hair loss does not necessarily lead to alopecia unless it lasts for a longer period of time.
But what is “less hair than normal”? On this side of obvious baldness, there are naturally flowing transitions from merely thin hair to alopecia. If alopecia occurs only in places, the hair density between diseased and healthy scalp areas can be compared. If this is not possible, guideline values can be used. Normal is 180 to 300 hairs per square centimeter of scalp. For blonde hair, typical hair densities tend to be in the range of the higher values, for black and red hair rather in the lower numbers. With increasing age, the hair density slowly decreases; this is also normal.
The term alopecia is a term you will often encounter on these pages: Most of the clinical pictures (or symptoms … not every hair loss has disease value) around hair loss are called alopecia. For example, doctors speak of androgenetic alopecia, alopecia areata, alopecia diffusa or scarring alopecia.
Effluvium is the medical term for hair loss. If you lose more hair than normal when combing, washing and “just like that” in your everyday life, this is called effluvium.
Again, the question arises as to what is normal. And here too, doctors and those affected can use guidelines as a guide: It is considered normal if up to 100 or 150 hairs are lost daily. The 100 applies to thinner hair, the 150 to thicker hair. When hair is washed, it can even be around 300 hairs. Of course, counting the number of hairs in the comb, on the pillow or in the bathtub drain is never really accurate – you will usually underestimate the number of hairs that go out.
If you suspect that you are suffering from hair loss, the dermatologist will first perform the hair plucking test and then, if you wish, analyse the current status of your hair follicles with a trichogram or tricho-scan. If no irregularities can be found, you can assume that there is no cause for concern at the moment: Perhaps you have overestimated the amount of hair that has fallen out?
A conspicuous trichogram indicates that effluvium does indeed exist and allows an additional distinction, namely that between anagenic and telogenic effluvium.
In anagen effluvium, hairs that are actually in the middle of their growth phase are lost  The reason is usually acute damage to the hair follicles from a few days to a maximum of one month ago due to physical influences, toxins, drugs or endogenous substances that disturb or prevent cell division. The hair produced by the follicles in the days following the damage has an abnormal, weakened structure and therefore tends to break off.
Since the majority of the hair is always in the growth phase (90% in healthy hair, and even in the case of disorders of the hair cycle still well over half of it), the anagen effluvium can frighten affected persons with very large amounts of hair falling out, up to practically complete hairlessness. Eighty to ninety percent hair loss is typical.
The best known triggers of anagen effluvium are radiation or chemotherapy for cancer. Not all cytostatic drugs used in chemotherapy lead to hair loss, but a number of them do (especially doxorubicin, daunorubicin, paclitaxel, docetaxel, cyclophosphamide, ifosfamide, etoposide, mechloroethamine, methotrexate and bleomycin ). Other possible causes are extreme malnutrition with a lack of protein and calories, poisoning with heavy metals such as thallium or mercury (in which case other symptoms of poisoning usually also appear) and side effects of high-dose medication. Aggressive inflammatory diseases of the hair follicles or the skin surrounding them (alopecia areata, systemic lupus erythematosus) also trigger anagen effluvium.
Many toxic influences leading to anagen effluvium only damage the currently dividing tissue of the hair follicles, while the “dormant” stem cells from which the follicle can regenerate in its next growth phase remain intact. (An exception are high-dose radioactive and x-rays, which can also attack the stem cells). Therefore, as long as there are no renewed damaging influences, new hair growth usually begins after one to three months. As a result of changes in the inner root sheath or the melanocytes of the hair follicles, the new hair can grow thicker or finer, curlier, smoother or greyer than before.
Predominantly in children up to the age of six years, the so-called Loose Anagen Syndrome occurs: Here the hair is not firmly anchored in the root sheath of the follicle and can therefore be pulled out painlessly without effort even during the growth phase – which naturally leads to high losses of anagen hair in many everyday situations. This is probably caused by genetic abnormalities in the lining of the inner root sheath. The problem usually disappears in later years – physicians suspect that the increasing influence of androgens during puberty stabilizes the follicular structure .
Telogen Effluvium is the most important and common form of hair loss  The diagnosis “Telogen Effluvium” confirms that hair loss is present. It limits the possible causes of hair loss by largely excluding the typical causes of anagen effluvium – but does not yet indicate the cause of the problem or promising treatment approaches. Telogenic effluvium can have many different causes. Only further diagnosis will enable more precise statements to be made.
Telogen effluvium causes the loss of hair that is in the resting phase. The pattern of hair loss is usually diffused over the entire head. The hairs that fall out or are plucked for diagnosis are not damaged: they are not broken off and do not have an abnormally shaped or narrowed hair shaft.
Telogen Effluvium is never as dramatic as Anagen Effluvium because the (always significant) proportion of scalp hair that is in the growth phase is not affected. The extent of hair loss through phases of Telogen Effluvium is approximately between 20 and 50% of the scalp hair, depending on the triggering cause.
An acute telogen effluvium does not become apparent until two to four months after the triggering event (or the beginning of a continuous damaging influence), which can make diagnosis difficult. A wide range of possible triggers is possible – and it may be that the cause cannot be identified despite extensive diagnostic efforts.
In order to understand the telogen effluvium, it is important to know that telogen hairs are lost anyway – at the latest at the end of the dormancy phase or at the beginning of the new growth phase. The 100 to 150 hairs that you can lose every day without worrying are predominantly telogen hairs.
A noticeably increased loss of telogen hair is generally a symptom of an instantaneous, long-term or chronic disruption of the hair cycle. It is usually caused by a shortening of the growth phase of the follicles. Paradoxically, however, a sudden shortening of the resting phase of the hair follicles can also lead to temporarily increased hair loss.
Telogen Effluvium through shortening of the anagen phase
Telogen Effluvium results when there are currently more hair follicles than normal in the resting phase. Although the proportion of daily telogen hairs leaving the body has not increased, the increased total number of telogen hairs means that you will still notice more hairs leaving the body.
The increased proportion of telogen hairs can be the result of a single trigger event (e.g. stress or a feverish illness) – in which case a large number of hair follicles have passed synchronously from the growth phase to the resting phase. The length of future growth phases remains uninfluenced by the trigger event, so the hair density returns to normal after a few months without further action.
Alternatively, the growth phase of the hair follicles can generally shorten due to hormonal changes, as a result of long-term drug treatment, possibly also due to nutrient deficiency or other, unexplained changes in the organism (e.g. unspecific physical inflammatory processes). If it is not possible to eliminate the underlying cause, the proportion of telogen hairs remains increased in the long term – although here too, a new balance with thinned hair but less hair loss usually sets in after about six months.
Telogen Effluvium by shortening the telogen phase
Temporary telogenic effluvium can also occur when the resting phase of the follicles is shortened. If many hair follicles enter the new growth phase synchronously from the resting phase, there is increased loss of telogen hair because the new hair growing in greater numbers than before pushes the old telogen hair out of the follicles. This type of effluvium can occur as a paradoxical symptom some time after starting treatment with the hair restorer Minoxidil and is actually interpreted as a sign that the treatment is working.