Hair grows in cycles. Each follicle has a period of active growth, a short transition and a resting period before an old hair is released. The follicles on your scalp are at different points in that cycle, which is why you can grow new hair and shed other strands on the same day.
This explains ordinary turnover. It does not, by itself, explain a widening part, a new bare patch or a sudden change in shedding. Those changes deserve individual assessment rather than a product chosen from a diagram.
The stages, in plain language
Anagen: the growing phase
During anagen, the follicle produces the hair shaft. Scalp hairs can stay in this phase for several years. The duration varies between people and follicles; it is one reason the length hair can reach differs from person to person.
Catagen: the transition
Growth stops and the lower part of the follicle changes as it moves towards rest. This is a much shorter stage, usually lasting a few weeks. It is a normal part of the cycle, not a sign that a shampoo has stopped working.
Telogen: the resting phase
The hair remains in place while the follicle rests for a period of months. A strand can therefore be on your head without actively getting longer.
Exogen: release of the old hair
The old strand is shed. Some explanations describe this separately as exogen; others include shedding within the resting stage. These are different ways of describing the same broad cycle, rather than competing accounts of how hair grows.
Why wash day can look dramatic
Loose hairs may remain caught among other strands until washing, brushing or detangling releases them. If you wash less often, several days of loose hair can appear together. Long strands also make a small collection look larger than the same number of short hairs.
A single shower is a poor baseline. When a change worries you, note when it started, how often you wash and whether your part or overall density looks different. Photographs taken in similar light and with the same parting are more useful to a clinician than comparing handfuls from different wash schedules.
Shedding and breakage are different
Shedding releases a whole hair from the follicle. Breakage happens along an existing strand. Short pieces, split ends and uneven lengths can suggest breakage, but a photograph or a look at the end of one hair cannot establish the cause of a change.
This distinction matters when reading hair-care claims. A conditioner that makes lengths easier to detangle is doing a different job from altering the growth cycle. Our guide to keratin in hair care explains what cosmetic conditioning can reasonably mean.
What belongs in an everyday routine?
Choose wash frequency around how your scalp feels and how much oil or styling residue accumulates. Apply shampoo to the scalp and conditioner where the lengths need it, following the label. Detangle without pulling and avoid making every wash a vigorous scalp-scrubbing session.
For a practical sequence, see our scalp washing and conditioning routine. These are grooming choices; they are not a way to synchronise follicles or promise faster growth.
When the cycle is not the whole answer
Seek a GP or dermatologist's advice for sudden or persistent changes, patchy loss, or a scalp that is painful or visibly inflamed. Bring a list of medicines and supplements you use. Do not assume a nutrient deficiency from hair appearance alone.
If you are considering a supplement because of shedding, read the questions to ask before buying a hair supplement. A change in your hair deserves an explanation before it becomes a shopping decision.
Further reading: DermNet's explanation of the hair cycle and the American Academy of Dermatology on shedding and hair loss.
