Hair loss is not always genetic; there are many reasons unexpected hair fall may happen, one of which is due to illness.
This subject has been in the news recently after Sarah Hyland, star of the long-running US comedy series Modern Family, spoke to the Refinery29 website about the hair loss she experienced following on-going issues with endometriosis and kidney dysplasia, as well as two kidney transplants. She also noted how her previously straight hair turned curly when it grew back.
Here Belgravia hair loss specialists explain the various reasons behind shedding following illness or surgery and some of the quirks that can occur when hair regrows.
"Various illnesses and medical conditions can cause shedding as a side effect of the stress they place on the body; this is because the body diverts its resources away from 'non-essential' functions, such as the hair growth cycle, so it can protect critical organs such as the heart and lungs, whilst fighting the health issue," advises Senior Hair Loss Specialist, Leonora Doclis. "The emotional stress which can accompany illness can also be a factor.
This can then causes a disturbance to normal hair growth, which results in diffuse hair loss from all over the scalp, presenting around three months later. This is known as Telogen Effluvium when it lasts for up to six months but, in more persistent cases - perhaps where an illness is on-going or longer-term - this can last more than six months and is classed as Chronic Telogen Effluvium, also known as Diffuse Thinning.
Although these are temporary hair loss conditions, they may be quite distressing as they can appear to come on suddenly with up to 30 per cent - sometimes more - of the hair being affected at once."
These types of hair thinning can also occur following surgery. As Doclis explains, "When someone undergoes major surgery, this can also cause a 'shock to the system', which again disrupts the hair growth cycle and can spark the same kinds of hair loss. Alternatively - or additionally - it may also cause sudden bald spots or patches from the autoimmune disorder Alopecia Areata to appear, though normal hair growth often returns naturally within 12 months in these instances."
Another illness-related issue that can cause temporary shedding is prescription medication used to treat the underlying health concern.
Belgravia Superintendent Pharmacist, Christina Chikaher, says "Many drugs list hair loss as a possible side effect on the patient information leaflet which accompanies the medication.
This is a form of Telogen Effluvium that occurs within approximately three months of starting the treatment, and should right itself naturally within six months, once the body has adjusted to the new drugs.
The most prominent exception to this being cancer drugs and therapies; it generally takes up to 12 months from the last session for hair loss from chemotherapy to regrow naturally - perhaps less if a cold cap was worn during treatment and the shedding was relatively moderate - though radiotherapy can result in permanent baldness as it destroys hair follicles as well as cancer cells."
Although Telogen Effluvium and Chronic Telogen Effluvium are both temporary, they are linked to permanent hair loss conditions.
"They can exacerbate existing cases of Male Pattern Baldness or Female Pattern Hair Loss, or even trigger the premature onset of these permanent, hereditary conditions where the individual has an existing genetic predisposition," notes Belgravia Hair Specialist, Rali Bozinhova.
"Telogen Effluvium and Chronic Telogen Effluvium can both present on their own or simultaneously alongside genetic hair loss, making any existing shedding seem worse than before. However, while Male and Female Pattern Baldness only affect the top of the scalp from crown to hairline and temple areas, Telogen Effluvium causes shedding from the entire scalp.
We advise anyone experiencing unusual levels of hair fall, persistent or sudden shedding to visit a dedicated hair loss clinic for a specialist consultation. That way a professional can assess your scalp and provide you with not only a diagnosis, but also personalised hair loss treatment recommendations, based on their findings and your medical profile."
In the majority of cases, the following timelines will see natural hair growth resume: up to 6 months for Telogen Effluvium, 6-12 months for Chronic Telogen Effluvium and around 12 months from the last chemotherapy session for chemo-induced Anagen Effluvium.
For those wanting to help accelerate their hair regrowth, Telogen Effluvium treatment courses are available for both the regular and chronic forms, depending on medical suitability.
When the does hair grow back, in some cases - typically following cancer treatment or Alopecia Areata - as was the case for Sarah Hyland, the hair may be a different colour or texture.
This tends to be a temporary issue which resolves itself within a full hair cycle or two, but it can cause changes to hair pigmentation, with it often appearing paler than before, or can leave previously straight hair, curly.
It is normal for this to happen and is not something to worry about unduly, however, if you are particularly concerned, an assessment and advice from a hair loss specialist should put your mind at rest.
The Belgravia Centre is a world-renowned group of a hair loss clinic in Central London, UK. If you are worried about hair loss you can arrange a free consultation with a hair loss expert or complete our Online Consultation from anywhere in the world for home-use treatment.
View our Hair Loss Success Stories, which includes the world's largest gallery of hair growth photos and demonstrates the level of success that so many of Belgravia's patients achieve.