Skin Care Education

Hair Thinning

A gradual reduction in hair density, strand diameter, or growth rate, distinct from bald patches or total hair loss.

What Is Hair Thinning?

Hair thinning describes a gradual change in how much hair is visibly present on the scalp, whether that means individual strands becoming finer, overall density decreasing, or the growth cycle shortening so hair sheds before it grows as long or thick as before. Unlike sudden or patchy hair loss, thinning tends to happen slowly, often over months or years.

Hair grows in cycles, moving between an active growth phase, a transitional phase, and a resting phase before shedding and starting again. Thinning typically reflects a shift in that cycle, with more hairs moving into the resting and shedding phases relative to how many are actively growing.

Thinning affects a significant proportion of adults at some point, and it is often the earliest visible stage of a longer pattern, which is part of why addressing it early tends to be more effective than waiting for more significant loss to develop.

Types of Hair Thinning

Diffuse thinning: an overall, even reduction in density across the scalp, often linked to hormones, nutrition, or stress.
Pattern thinning: a genetically driven, progressive thinning that typically follows a recognisable pattern, at the crown or hairline.
Telogen effluvium: a temporary, more sudden shedding phase triggered by a specific event such as illness, surgery, or significant stress, usually noticed two to three months after the trigger.
Postpartum thinning: a common, typically temporary thinning phase that occurs as hormone levels shift back after pregnancy.

Causes and Contributing Factors

Factor	Description
Genetics (pattern thinning)	The most common cause in both men and women, driven by genetic sensitivity to hormones that gradually shrink hair follicles over time.
Hormonal changes	Pregnancy, postpartum shifts, perimenopause, menopause, and thyroid changes can all affect the hair growth cycle.
Nutritional factors	Iron deficiency, low protein intake, and certain vitamin deficiencies can affect the hair follicle’s ability to sustain healthy growth.
Stress and illness	Significant physical or emotional stress can push a larger-than-usual number of hairs into the shedding phase at once.
Scalp health	A compromised scalp environment, from buildup, inflammation, or poor circulation, affects how well the scalp supports active growth.

Frequently Asked Questions: Hair Thinning

It depends on the cause. Thinning driven by a temporary trigger such as stress, illness, or nutritional deficiency often improves once the underlying trigger is addressed. Thinning driven by genetics tends to be progressive, though its rate and visible impact can often be managed with the right ongoing approach.

Genetic pattern thinning can begin as early as the twenties for some people, while for others it does not become noticeable until their forties or fifties. Hormonally driven thinning is closely tied to specific life stages and can appear at any adult age.

Yes. The scalp is the environment the hair follicle grows in, and a scalp affected by buildup, inflammation, or poor circulation is a less supportive environment for active, healthy growth.

Genetic thinning cannot be fully prevented, though its progression can often be slowed with early, consistent care. Thinning caused by nutritional, hormonal, or stress-related factors can often be meaningfully reduced by addressing those underlying factors directly.