Hair fall: the five things we test before we treat anything

Almost every patient who walks in for hair fall has already tried oils, supplements and a shampoo someone recommended. Very few have had the one thing that changes outcomes: a diagnosis.

First: is it actually abnormal?

Losing some hair daily is normal — roughly 50–100 strands. What matters is not the count on a bad day but the pattern and the trend: is the parting widening, is the ponytail thinner, is there more scalp visible in overhead light, and how long has it been going on? A phone photo from six months ago is often more diagnostic than any single test.

Second: which type of hair loss

The two commonest are quite different problems that look similar to the person experiencing them.

Telogen effluvium

Diffuse shedding, usually starting 2–3 months after a trigger — an illness, a fever, surgery, childbirth, a crash diet, severe stress. Hair comes out from all over rather than a specific pattern. The good news: it is usually self-limiting once the trigger is corrected.

Androgenetic (pattern) hair loss

Follicles progressively miniaturise — hair becomes finer and shorter before it stops. In women it widens the parting; in men it recedes the hairline and thins the crown. It does not resolve on its own, and earlier treatment protects follicles that are still viable.

Third: the blood work that actually matters

Standard workup for non-scarring hair loss typically includes a complete blood count, thyroid function, serum ferritin, vitamin D, vitamin B12, and iron studies — with zinc where indicated.

Ferritin deserves a special mention. It is the most frequently missed test in hair-loss workups, because clinicians often check haemoglobin or a CBC and stop there — yet ferritin is the correction that most reliably accelerates recovery when it is low. Many hair specialists aim well above the “normal” laboratory floor for hair regrowth purposes.

Worth knowing: the evidence here is not unanimous. A 2024 study comparing chronic telogen effluvium patients with controls found several of these markers did not differ significantly between groups, while zinc, selenium and the copper-to-zinc ratio did. Which is exactly why tests are interpreted alongside examination rather than treated as a verdict on their own.

Fourth: the scalp itself

Dandruff, seborrhoeic dermatitis and folliculitis create an inflamed environment that worsens shedding. Persistent itching and scratching add mechanical damage on top. Treating the scalp is unglamorous and frequently the step that makes everything else work.

Trichoscopy — examining the scalp under magnification — tells us about miniaturisation, inflammation around follicles, and scarring. Scarring alopecias behave completely differently and need urgent, different treatment, because lost follicles in scarring conditions do not come back.

Fifth: the timeline you can realistically expect

Hair biology is slow, and any clinic promising speed is selling something.

• Weeks 4–8: shedding usually settles first. This is the earliest honest sign of progress.
• Months 3–4: short regrowth appears at the hairline and parting.
• Months 6–12: visible density change — tracked with standardised photographs, not impressions.

Then, and only then, treatment

Once the cause is clear, options range from medical therapy and correcting deficiencies to in-clinic regenerative treatments such as GFC or PRP, and for advanced pattern loss, transplantation. Which of those helps you depends entirely on the diagnosis — which is the whole point of this article.