Diffuse hair loss can be a particularly difficult form of hair loss to cope with psychologically. Affecting men and women of all ages and often occurring suddenly, it is characterized by thinning and shedding across the whole scalp.
There are a range of causes, and because possible treatments differ based on the particular trigger it is useful to get a good overview of what diffuse hair loss is and what’s behind it. This article does exactly that, and also looks at when and how something can be done to stop the hair loss and aid regrowth.
What is diffuse hair loss?
Diffuse hair loss occurs evenly across the scalp rather than in specific areas. To understand what is happening some knowledge of the hair growth cycle is necessary. We have explained the cycle in detail before, and that article is helpful for a more complete understanding of diffuse shedding. Very simply though, the hair growth cycle consists of three phases - anagen, catagen and telogen. The anagen phase is a growth stage, the catagen phase is a transitional stage, and the telogen phase is a resting stage at the end of which the hair shaft is pushed out of the follicle, i.e. it sheds.
Individual hairs cycle independently of one another. This means that at any one moment, there are hairs in each phase (and at different stages of each phase). Some hairs are growing, while some are shedding and others are simply resting. The number of hairs on the head therefore remains fairly stable, and although some hair sheds each day, this shedding is not particularly noticeable and is not abnormal.
Diffuse hair loss is what happens when one of the cycles is disrupted. The most common form of this diffuse shedding is when hairs in the growth phase prematurely move to the shedding phase. This is called telogen effluvium. At the end of the premature telogen phase (about three months later), the shedding will be very noticeable as more hairs will be in this phase than normal. While this is happening, fewer hairs will be in the anagen phase and so the loss becomes more apparent as there are fewer hairs growing and replacing.
There is another form of diffuse hair loss, which results in termination of the anagen phase. This is most commonly caused by treatments such as those involving radiation. Female pattern hair loss also sees a disruption in the hair growth cycle which can result in diffuse loss - there is a progressive reduction in cycle times.
What is the difference between diffuse and localized hair loss?
While diffuse hair thinning occurs across the scalp with a general distribution, localized hair loss occurs in specific spots. Localized hair loss is not caused by this same cycle disruption, and can have a large range of forms and causes.
What causes diffuse hair loss?
We have noted telogen effluvium, anagen loss and female pattern hair loss as broad causes in our explanation of what diffuse hair loss is. We’ll now be more specific, looking at what the actual triggers of diffuse hair loss are, especially as regards telogen effluvium.
Stress can cause diffuse hair loss. Psychological stress is one possible trigger, with evidence of acute telogen effluvium occurring after extreme stress, however evidence of chronic telogen effluvium as a result of emotional stress is weaker. A more common trigger and better evidenced is physiological stress. Such stresses include things like surgery, trauma and systemic illness. Where there is a distinct triggering event, the resulting diffuse hair loss will likely be seen about three months later. This typical time period can help someone who is suffering diffuse shedding to work out what the trigger may have been.
Diet and nutrition can also be causes of diffuse hair loss. Zinc and iron deficiencies can trigger telogen effluvium and there are even suggestions that crash dieting can as well.
A number of medical conditions can cause telogen effluvium, and treatment of conditions (not necessarily TE-causing conditions themselves) can do so too. The list of conditions that can trigger diffuse hair loss is long, encompassing autoimmune diseases, inflammatory disorders and systemic disorders. Likewise, the list of drugs that sometimes cause diffuse shedding is long and includes retinoids, androgens, antidepressants and oral contraceptives.
How do you fix diffuse hair loss?
Telogen effluvium is a ‘self-limiting condition’, which means that once the trigger is removed (e.g. a drug is stopped or a nutritional deficiency is fixed) the issue will resolve. This will not be immediate and full recovery may take upwards of a year. Chronic telogen effluvium (which lasts longer than six months) is believed to also be self-limiting but there is a lack of research looking at the longer term. It is very important that any ongoing triggers are identified early, so they can be removed and the recovery process can start.
There are a few different options available to those whose diffuse hair loss is part of female pattern hair loss. Minoxidil is sometimes recommended, with effective results possible but risks of additional hair shedding and scalp irritation can be off putting. ProCelinyl offers an alternative to minoxidil that doesn’t have any of these undesirable side effects, but which is highly effective in improving the appearance of thicker, fuller hair.
Two other options, which offer very different approaches are hair camouflage and hair transplants. Hair camouflage examples include hairpieces and thickening fibers. These temporary solutions might be appealing where someone has been advised by their doctor that their diffuse hair loss will be short-lived, i.e. in the case of acute telogen effluvium. Hair transplants offer a more drastic, invasive and risky option, and would only be appropriate for those facing permanent hair loss and perhaps not even in that case.