Journal · Hair loss causes & types · by Dr. Steven Goh

Hair Loss Causes: Types, Triggers & When to Get Help

Hair loss usually comes from one of a few broad causes: genetics (pattern hair loss), a shock to the system such as illness, stress or childbirth (telogen effluvium), patchy autoimmune loss (alopecia areata), tension from tight styles, or ageing. Working out which one applies is the first step, and sudden or patchy loss should be checked by a doctor.

Why the cause matters

People often ask us for "the best hair loss treatment" before they know what kind of hair loss they have. That is understandable, but it is the wrong way round. Different causes behave differently: some are temporary and settle on their own, some are gradual and long-term, and a few need medical care. Knowing the likely cause shapes what is sensible to try, what is a waste of money, and when a doctor needs to be involved.

This guide is the starting point of our hair loss causes series. It covers the main types in plain English and links to more detailed articles on women's hair thinning and receding hairlines and crown thinning in men.

The main types of hair loss

Pattern hair loss (androgenetic alopecia)

This is the type most people mean when they talk about hair loss. It is strongly linked to genetics and hormones, and it tends to develop gradually.

• In men it usually shows as a receding hairline at the temples, thinning at the crown, or both.
• In women it more often appears as diffuse thinning over the top of the head and a parting that looks wider than it used to.

Pattern hair loss is gradual. Hairs in affected areas tend to become finer and shorter over time, which is why the scalp can start to show through even before there are obvious bald patches.

Telogen effluvium (shedding after a shock)

Hair grows in cycles. A significant physical or emotional stress, such as a high fever, an illness, surgery, a crash diet, bereavement or a very difficult period at work, can push more hairs than usual into the resting phase at the same time. Those hairs then fall out together, typically some weeks or months after the event.

The delay is what confuses people. By the time hair starts coming out in the shower, the stressful event may feel long past. Shedding of this kind is often temporary, but it can be very distressing while it lasts.

Postpartum shedding

Many new mothers notice heavy shedding a few months after giving birth, as hormone levels shift back. It is a form of telogen effluvium, and it is usually temporary. We cover it in more depth in our guide to hair thinning in women.

Alopecia areata (patchy loss)

Alopecia areata usually shows as smooth, round patches of hair loss. It is an autoimmune condition, so it needs a medical diagnosis. Some people later look for cosmetic options to make stable patches less noticeable, but that should come after a doctor has assessed the condition, not instead of it.

Traction alopecia

Repeated tension from tight ponytails, buns, braids, extensions or headwear worn tightly can thin the hairline and the edges over time. Catching it early and easing the tension matters.

Age-related thinning

As we get older, many people find their hair becomes finer and less dense overall. This is a natural process, though it often overlaps with pattern hair loss.

Other contributors

Nutrition, scalp health, some medications and medical conditions such as thyroid problems can all play a part. These are areas where a doctor can arrange the right checks. Our scalp health guide covers everyday issues such as an oily, itchy or flaky scalp.

How to tell what you might be dealing with

You cannot diagnose yourself from an article, but you can notice useful clues to discuss with a professional:

• Pattern: Is the loss at the temples and crown, across the top, along the edges, or in round patches?
• Speed: Did it happen gradually over years, or suddenly over weeks?
• Timing: Was there an illness, a birth, a big life event or a change of medication two to four months before the shedding began?
• Scalp symptoms: Is there itching, redness, scaling, soreness or pain?
• Family history: Did parents or grandparents thin in a similar way?

Taking monthly photos in the same light and from the same angles is a simple way to track change honestly. Memory is unreliable when you are worried about your hair.

What a scalp assessment looks at

At a Folli-Doc consultation, the first step of the Folli-Doc process is a digital scalp analysis. It maps thinning zones and density, looks at the condition of the existing hair and scalp, and notes the natural growth direction and texture of the hair. It ends with a discussion of realistic expectations. This kind of assessment is not a medical diagnosis, and where something looks like it needs a doctor, that should come first.

Where cosmetic and scalp-care options fit

Once medical causes have been considered, many people want two things: hair that looks fuller now, and a healthier scalp environment over time. Folli-Doc's Simulation & Stimulation treatment is designed around that dual approach, combining a cosmetic hair simulation layer with scalp bio-stimulation. Our options compared guide explains how it sits alongside topicals, PRP and transplants, and our article on grey and thin hair explains why contrast changes how full hair looks.

No treatment works for everyone, and nobody can honestly promise a set result. What a good assessment can do is help you understand what is going on and choose sensibly.

Summary

Most hair loss falls into a handful of patterns, and the pattern, speed and timing of your loss are the best clues. Gradual thinning in a typical shape suggests pattern hair loss; sudden shedding after a shock suggests telogen effluvium; round patches or a sore, inflamed scalp need a doctor. With the cause in mind, you can choose care that fits rather than guessing.

Frequently asked questions