Noticing more hair in the shower drain or on your hairbrush can be genuinely alarming. The first thing worth knowing is that losing hair every day is completely normal. The average person loses between 50 and 100 hairs per day, and this can increase to considerably more during periods of physical or emotional stress. Knowing what is normal, what triggers temporary increases, and what might signal a condition that needs attention changes how rationally you can respond.
Normal shedding versus hair loss
Hair grows in cycles. Each follicle cycles between a growth phase (anagen, lasting 2-7 years), a transitional phase (catagen, lasting 2-3 weeks), and a resting phase (telogen, lasting 3-4 months) before the hair sheds and the cycle begins again. At any given time, around 85-90% of your hair is in the anagen phase and 10-15% is in telogen.
Increased shedding, medically called telogen effluvium, occurs when a larger proportion than normal enters the telogen phase simultaneously, then sheds together two to four months later. The cause is almost always something that happened two to four months before the shedding appears, which is why people often fail to connect the trigger to the symptom.
Common triggers for telogen effluvium include major illness or fever, surgery, significant weight loss, crash dieting, severe psychological stress, childbirth, and stopping hormonal contraceptives. The hair loss is diffuse (evenly distributed across the scalp), temporary, and resolves as the follicles return to their normal cycle, usually within six months of the trigger resolving.
When it might be something more
If hair loss is concentrated in specific patterns, that is a different situation from diffuse shedding. Receding hairlines, thinning at the crown, or circular patches of complete hair loss indicate conditions that need medical assessment.
Androgenetic alopecia (pattern hair loss) affects a significant proportion of both men and women. In men, it presents as hairline recession and crown thinning. In women, it is more commonly generalised thinning across the crown with a widening parting. It is hormonally driven, involving the androgen DHT’s effect on genetically susceptible follicles, and it is progressive without treatment.
Alopecia areata is an autoimmune condition causing patchy hair loss. It can resolve spontaneously, or progress. It requires dermatological evaluation.
Iron deficiency and thyroid disorders are among the more common medical causes of diffuse hair thinning. A blood test checking ferritin (stored iron), full blood count, and thyroid function (TSH, T3, T4) is the standard first investigation for unexplained hair loss in a person without obvious pattern loss. These are treatable, and addressing the deficiency often resolves the hair loss.
Nutritional factors with real evidence
Iron deficiency is one of the most common nutritional drivers of hair loss in women of reproductive age. Even when haemoglobin levels are normal, low ferritin (below approximately 30 mcg/L) is associated with increased shedding in research. Correcting ferritin through diet or supplementation often improves this within several months.
Zinc deficiency affects hair follicle function and is associated with hair loss. It is a relatively common deficiency globally. Foods rich in zinc include oysters, red meat, seeds, and legumes. Supplementation can cause problems (including copper deficiency) if taken excessively; address with diet first where possible.
Biotin (vitamin B7) deficiency is genuinely rare in adults eating a varied diet, but it is aggressively marketed as a hair supplement. The evidence for biotin supplementation improving hair loss in people without a documented deficiency is essentially absent. Most people taking biotin for hair loss are wasting money and potentially interfering with certain blood test results.
Protein deficiency, seen in severe caloric restriction or very low-protein diets, can cause hair loss because the body prioritises protein for more critical functions than hair growth. Hair is predominantly keratin protein, and inadequate protein intake starves follicles of building material.
Scalp health and hair care factors
Scalp conditions including seborrhoeic dermatitis, psoriasis, and folliculitis can contribute to hair loss by affecting the follicle environment. Treating the underlying scalp condition generally improves hair loss associated with it.
Traction from tight hairstyles (traction alopecia) causes hair loss over time at the hairline and where the tension is applied. This is particularly common in people who wear their hair in tight braids, weaves, or ponytails chronically.
Scalp massage has modest evidence for increasing hair thickness. A small Japanese study found that four minutes of daily scalp massage over 24 weeks increased hair thickness. The mechanism appears related to mechanical stimulation of follicles rather than circulation, though both may play a role. It is low risk, and a scalp serum applied during massage combines two potentially beneficial approaches.
A well-formulated hair serum applied to the scalp can support the follicle environment, improve scalp condition, and work synergistically with regular massage. Look for formulations containing ingredients like rosemary oil, which has emerging evidence for hair growth support.
Rosemary oil: the natural option with real research
A 2015 randomised controlled trial published in SKINmed compared 2% minoxidil solution (a pharmaceutical hair loss treatment) with rosemary oil applied topically over six months. Both groups showed similar hair count increases by six months, and rosemary oil caused less scalp itching than minoxidil. This is a single study, and replication would strengthen the evidence, but it is considerably more rigorous than the research behind most natural hair growth claims.
Rosemary contains carnosic acid, which appears to stimulate nerve growth factor, which in turn may support follicle regeneration. The concentration used in the study was equivalent to diluting rosemary essential oil to about 2-3% in a carrier oil.
When to see a doctor
If hair loss is rapid, patchy, associated with other symptoms (fatigue, weight changes, irregular cycles), or is not resolving after six months, blood tests and a dermatologist’s opinion are worth having. Early androgenetic alopecia responds better to treatment before significant follicle loss has occurred. Conditions like alopecia areata, scalp infections, or systemic disease need diagnosis rather than home treatment.
For unexplained diffuse shedding without an obvious trigger, start with blood tests checking ferritin, iron, thyroid, and zinc. Rule out the common treatable causes before investing in treatments that may not address the actual problem.