Men's Thinning Hair and Hair Loss: What Causes It? DHT Hormone, Genetics, and Warning Signs You Shouldn't Ignore, in Phitsanulok 2026

I understand this worry well. When many men first notice more hair coming out on the comb, a forehead that looks wider in photos, or a crown where the scalp starts to show in sunlight, the first feeling is usually not just "I'll miss my hair" — it's a quiet anxiety: "Will I look older? Is it still fixable?" Let me say up front that this is completely understandable, and in most cases there are ways to care for it. We just need to understand the true "root cause" first.

Which Hair Loss Is "Normal" and Which Means "Trouble Is Starting"

If you come to see me about hair loss, the first question many people ask is, "How much hair loss per day counts as abnormal?" Let me put your mind at ease first — hair shedding is a natural process. Every strand of hair has its own cycle: a growth phase, a resting phase, and then a shedding phase so a new strand can grow in its place. That's why most people lose around 50–100 strands per day, which is perfectly normal.

What you really need to watch is not the "number of strands shed" alone, but rather "whether new hair keeps up." If hair sheds but new strands keep coming in to replace it, the overall thickness doesn't change. But if the new hair that grows starts to come in "smaller, thinner, shorter" until it can't keep pace with what's falling out — that's the point where you start to see more scalp, and it's a sign you should start paying attention.

What Most Men's Thinning Hair Actually Is (Androgenetic Alopecia)

The most common form of thinning hair in men has the medical name androgenetic alopecia, or what people generally call "hereditary thinning hair" or "male pattern baldness." This condition is genuinely very common — medical data indicates that about half of all men will begin to develop it by around age 50, and many start much earlier than that.

The word androgenetic comes from two words combined: "andro" (male hormone) and "genetic" (heredity), which already hints at the root cause in its name — it is the interplay of "hormones" and "genes passed down within the family." It is not a contagious disease, not the result of poor self-care, and not anyone's fault.

The distinctive feature that sets it apart from other types of hair loss is that it usually occurs in a specific pattern — starting with the frontal hairline on both sides receding into an M shape, followed by the crown gradually thinning out, while the hair on the sides and back of the head usually remains thick, because the follicles in those areas are "not sensitive" to the problematic hormone.

The Main Culprit: How the DHT Hormone Acts on Hair Follicles

Now we come to the star of the story (really, we should call it the villain) — a hormone called DHT (dihydrotestosterone). Let me explain it in a way you can understand without being a doctor.

Where Does DHT Come From?

A man's body normally already has a male hormone called testosterone. A portion of that testosterone is converted by an enzyme called 5-alpha reductase into DHT, which is a stronger hormone. DHT serves several good functions in the body, but it has a "side effect" on the hair follicles of some people.

So How Does It Harm the Follicles?

In people whose follicles are genetically "sensitive" to DHT, when DHT binds to the receptors on the follicle, it gradually causes what is called miniaturization — the follicle "shrinks smaller and smaller." The growth cycle shortens too, so the hair that grows in each cycle becomes smaller, thinner, and lighter in color, until finally the follicle becomes too small to push out a strand at all. This process is gradual, taking years — it doesn't happen overnight.

This is why many approaches to caring for men's thinning hair aim at "managing DHT" or "stimulating the still-living follicles to start working again," which I'll explain in detail in the article Treating Men's Thinning Hair Without Surgery — What Options Are There

What About Genetics? Why Some Men Go Bald While Still Young

A question I hear very often is, "My dad isn't bald, doctor, so why is my hair starting to thin?" or "Look at my grandfather on my mother's side — he's completely bald." The genetics of thinning hair are more complex than many people understand.

The old belief that "look at your maternal grandfather's head and you'll know the future of your own" is partly true, but not entirely. The truth is that the genes for thinning hair can be inherited from both the father's and the mother's side, and it involves many genes together, not a single gene. That means even if your family members have thick hair, you can still inherit genes that make your follicles sensitive to DHT.

Genetics determine the "sensitivity" of the follicles to DHT, and they also affect the "age at which thinning begins" and the "speed at which it progresses." People who start thinning in their early 20s therefore usually have more sensitive genetics and tend to progress faster if they don't take care of it early.

Not Always Hereditary — Other Causes of Thinning Hair

Although thinning hair from genetics combined with hormones is the most common, I want to remind you that not every type of hair loss is hereditary. And this is an important reason why "finding the true cause" before starting treatment matters so much — because each cause is treated in a completely different way.

If your hair loss happens "quickly," "diffusely all over the head," or after a particular event, the cause may not be genetic but rather one of the following instead.

Often patients have several causes mixed together — for example, they already have a genetic tendency to thinning, and then hit a period of heavy stress or nutritional deficiency at just the wrong time, causing the hair to fall out faster than it should. A medical assessment therefore helps distinguish what is the main culprit and what is an accelerating factor that can be fixed.

Early Warning Signs — The Sooner You Know, the Better

If you're wondering whether you've started to have a problem yet, I've gathered the early signs to watch for. Not to make you anxious, but to help you "notice in time" — while it's still easy to care for.

• The frontal hairline receding, especially at both temples, until the forehead takes on an M shape
• The crown becoming sparser, with the scalp showing more clearly in light or when the hair is tied back
• Hair strands becoming smaller and weaker, with new hair growing in thinner and shorter than before
• Increased hair loss continuing for several months, not just a short burst of heavy shedding that then stops
• Harder to style, with hair looking flatter and not as full as it used to be

Time to Stop Believing These — Myths About Hair Loss

There are beliefs about hair loss that have been passed down for a long time, and I see patients worry about them so often that they delay starting real care. Let me clear them up to put your mind at ease.

• Does wearing a hat often cause hair loss? Not true. Wearing a hat normally does not cause hereditary thinning hair.
• Does washing your hair often, or washing it at night, cause hair loss? Not true. The hair that falls out while washing is the strands that were already due to shed.
• Does shaving your head make hair grow back thicker? Not true. Shaving doesn't change the follicles; it only makes the newly grown strands look thick while they're short.
• Once hair is thinning, it can't be fixed and you just have to let it go? Not always true. If the follicles are still alive, there are several ways to help slow it down and restore it.

Dwelling on these myths often makes people waste time fixing the wrong things, then start real care too late — which is a great pity.

Can It Be Treated? Why "Starting Early" Matters So Much

The question everyone most wants answered — "So can it be fixed, doctor?" The answer is in most cases, there are ways to care for it, especially when the cause is clearly known and you start while the follicles are not yet dead. The key is not to "revive dead hair," but to "keep the living follicles with us for as long as possible" and to stimulate the shrunken follicles to start working again.

Non-surgical approaches come in several levels, from using medications that manage DHT or stimulate the follicles, to procedures that help restore the scalp and follicles — such as platelet-rich plasma (PRP) injections, exosomes, or scalp mesotherapy — each suited to a different stage and a different goal. I've compared them all in the article Treating Men's Thinning Hair Without Surgery — What Options Are There and in Which Types of Thinning Hair Can Be Treated, and When Should You Start

Consult About Thinning Hair in Phitsanulok — de Pry Clinic

If you've started to notice changes in your hair and want to know "what exactly is causing it in my case," Dr. Time at de Pry Clinic, Phitsanulok personally cares for every case of thinning and hair loss — beginning with sitting down to talk and finding the true cause first, examining the scalp and assessing the stage of the thinning, and then planning non-surgical care to suit each person's cause and lifestyle, rather than handing everyone the same single package.

Many patients travel to consult in Phitsanulok from nearby provinces — Phichit, Sukhothai, Uttaradit, Kamphaeng Phet, and Phetchabun — because they want someone who provides continuous care as a real doctor, not just someone who sells a course and is done. Whatever the outcome turns out to be, I'm here, caring for you and following up on your progress. If you're still not sure what stage your hair is at, you can always make an appointment to come in for a chat and assessment first.

References and Verification

I want you to be able to check the information I used to write this article for yourself — just click to read the originals:

• NHS (United Kingdom) — information on the causes of hair loss and various thinning conditions, along with guidance on when to see a doctor: nhs.uk
• Cleveland Clinic — explains men's thinning hair (androgenic alopecia), from the DHT mechanism and stages of the condition to care options: my.clevelandclinic.org
• American Academy of Dermatology (AAD) — covers causes of hair loss and thinning beyond genetics, such as stress, thyroid, and nutritional deficiency: aad.org
• PubMed Central (PMC) — a review of current approaches to managing androgenetic alopecia, confirming that the medications with the main evidence base are minoxidil and finasteride: pmc.ncbi.nlm.nih.gov