Genetics, hormones, illness and hair care can affect hair in different ways. A useful assessment works out which process is relevant to you, rather than treating every possible influence as a cause.
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“Why is my hair thinning?” sounds like one question, but it can describe several different problems. Hair may be shedding more quickly, gradually growing finer, breaking along the shaft, or disappearing from an inflamed area.
The first step is to work out which of those processes is happening. Otherwise, it is easy to build a long list of possible influences and assume you need to correct all of them.
Some people do have overlapping causes. A temporary shed can reveal pattern thinning that was already developing. That does not mean every case must involve an elaborate combination of hormonal, nutritional and lifestyle problems.
Pattern hair loss runs in families, but there is no single gene that reliably predicts everyone’s outcome. Large genetic studies have identified many associated regions across different chromosomes. The familiar idea that it comes only from your mother’s father is too simple.
In male pattern hair loss, inherited biology helps determine which follicles respond to androgens by gradually miniaturising. That is why people with similar hormone levels can have different hairlines and different rates of change.
A family history is useful context, not a timetable. Having a relative with extensive loss does not tell you exactly what will happen to your own hair, or how you will respond to treatment.
DHT is an important part of male pattern hair loss. It acts on susceptible follicles, shortening productive growth and contributing to finer hairs. This can happen when blood hormone levels are normal.
Female pattern hair loss has a more complex relationship with androgens. Normal results do not rule it out, and an abnormal result does not automatically explain every change in the scalp.
Thyroid disease can contribute to diffuse hair changes. Menstrual irregularity, acne or increased facial hair may point towards a broader endocrine assessment. The decision to test should follow the history and examination rather than a generic promise to “balance your hormones”.
Pregnancy and the months after birth can also change hair cycling. Postpartum shedding has a different course from gradual pattern thinning, although the two can overlap.
Telogen effluvium is a common explanation for increased diffuse shedding after a significant trigger. Illness, surgery, childbirth, substantial weight loss and nutritional strain are recognised examples.
The delay matters. Hair may begin shedding after you otherwise feel recovered, because the affected follicles have moved through the resting phase before releasing their hairs. The most recent change in your routine may therefore be unrelated.
Some medicines can also affect growth or shedding. If you suspect a link, discuss the timing with the prescriber. Do not stop an important medicine solely because hair loss appears in an online side-effect list.
Hair growth needs adequate nutrition. Insufficient energy or protein and some nutrient deficiencies can contribute to shedding. Correcting a genuine problem is useful; taking extra supplements when you already have enough is a different proposition.
Excessive amounts of some nutrients, including vitamin A and selenium, can themselves cause hair loss. More is not automatically better, even when the packaging says the product is designed for hair.
Hair care can affect the shaft and the follicle in different ways. Repeated bleaching or high heat may cause breakage. Tight or heavy styles can pull on follicles and produce traction alopecia. These problems need changes directed at the actual source of damage.
Smoking, poor sleep and metabolic health are studied in relation to hair loss. Much of that evidence is observational, which makes it difficult to separate cause from associated behaviours and health conditions. It cannot tell you that one stressful month caused your particular pattern of recession.
Looking after your general health remains worthwhile. It should not become an endless attempt to optimise every variable in the hope of overriding inherited follicle biology. Nor should hair loss be treated as evidence that you have failed to look after yourself.
Sun protection is sensible for exposed scalp skin. It should be recommended for that reason without implying that sunscreen has been shown to reverse pattern hair loss.
Pain, burning, marked redness, scale or a rapidly changing patch deserves medical assessment. Inflammatory conditions can require treatment that is very different from standard pattern hair loss care, and scarring disorders can permanently damage follicles.
A good assessment brings the timeline, distribution and examination together. It may lead to targeted tests, or it may provide a diagnosis without a large blood panel.
I would aim for a clear explanation of the main problem and any relevant contributors. That gives you a more useful plan than treating every theory you encounter as something else you must fix.
