Hair loss – or alopecia – can affect both men and women and can be both temporary and permanent.
However long it lasts, balding can be a source of great emotional distress to sufferers.
It can happen for a variety of reasons, including if you are a woman who has just given birth.
Known as postpartum hair loss, it happens due to natural changes in hormone levels after labour.
Keeping her thick, long locks was something Hollyoaks actress Jennifer Metcalfe was keen to do after being pregnant with her son Daye, who was born in August.
“Everyone was telling me that once your baby arrives, you start to lose your hair,” she told Express.co.uk.
“I had never heard of postpartum hair loss before and went into panic mode.
“While I was more than happy to put on weight or have sleepless nights, I just didn’t want to lose my hair.
“To prevent it falling out and to retain its thickness I used a hair regrowth treatment called Regrowz, and saw a difference in about three weeks.”
In addition to postpartum hair loss there are a number of other causes for a thinning mane.
Too much Vitamin A
Taking too high a dose of vitamin A supplements could cause hair loss, according to the American Academy of Dermatology.
The Department of Health recommends you have no more than 1.5mg a day.
One of the best ways to get the right amount of vitamin A, which is important for your immune system and boosting vision, is through diet.
Foods rich in the nutrient include cheese, eggs, oily fish, yoghurt and liver.
Your genes
In the UK, around half of men experience male pattern baldness by the age of 50 years.
According to the NHS, it is hereditary and due to oversensitive hair follicles.
The newly-engaged Prince Harry is thought to be suffering from male pattern baldness.
A doctor has suggested his hair loss appears to be genetic since his brother Prince William and father Prince Charles are also balding.
A vegan diet
They may be increasingly popular, but vegetarian and vegan diets can also lead to hair loss.
This is because it can make it easier to miss out on nutrients vital to hair growth, such as iron.
“Iron deficiency is a factor in hair loss since it’s necessary for hair growth,” Dr Hilary Jones, a GP, told Express.co.uk.
“With a lot of people shunning meat – possibly due to vegan and vegetarian diets – it is possible people are missing out on the nutrient.”
Stress
High levels of stress can likewise cause hair loss.
According to the Mayo Clinic, heightened emotion can push large numbers of follicles into a resting phase which then means they fall out from combing or washing within a few months.
Medication
Certain prescribed drugs can trigger you to lose your hair.
These include blood thinners to prevent clots, and blood pressure-lowering drugs, such as beta-blockers.
Additionally, nonsteroidal anti-inflammatory drugs (NSAIDs), including ibuprofen, and antidepressants can also cause your mane to thin.