Shedding vs Breakage: The Bulb Test Tells You in Seconds

Look at the root end. A shed hair is full length with a small white or translucent bulb, the keratin club that held it in the follicle, while a broken hair is a short, uneven fragment with frayed or split ends and no bulb. Shedding is driven by hormones, stress, illness, and the hair cycle; breakage is caused by bleach, heat, friction, and chemical processing. Losing 50 to 100 hairs a day is normal.

The shower drain is full of hair, and the question that decides what to do about it is the simplest one in trichology: does the hair have a bulb? A shed hair leaves the follicle whole, with a tiny white bulb at the root end. A broken hair snaps somewhere along the shaft, and the fragment has no bulb at all. One is a cycle event. The other is structural damage. Treating breakage like shedding, or shedding like breakage, wastes months.

The distinction is dermatological biology versus fiber physics. Shedding, clinically termed telogen effluvium when excessive, is an internal process involving the hair growth cycle. Breakage is a mechanical failure of the hair shaft. At any given time, roughly 85 to 90 percent of scalp hairs sit in the anagen, or active growth, phase, while 10 to 15 percent rest in the telogen phase, and losing 50 to 100 telogen hairs a day is standard baseline turnover for a healthy scalp.

The bulb test, step by step

Collect the fallen strands from your brush, shower drain, or clothing and lay them on a contrasting, well-lit surface. A plain white sheet works: lean forward, run your fingers through your hair for thirty seconds, and let everything fall onto the sheet. Inspect the ends under good light, or a low-power magnifying loupe if you have one.

If the majority of hairs match your full hair length and display a tiny, rounded, whitish dot at one end, you are seeing shed hairs. That dot is the non-pigmented keratinized base of the resting hair shaft, the club hair bulb, and it confirms the entire hair left the follicle naturally. If the strands lack a bulb on both ends, show uneven lengths, or look frayed like a frayed thread, with rough, jagged ends, split ends, or tiny white dots along the shaft, you are seeing structural breakage, and the fix is in how the hair is handled, not in the follicle.

What shedding means, and when it is telogen effluvium

Telogen effluvium is a diffuse, non-scarring form of hair shedding first described clinically by Dr. Albert Kligman in 1961. An acute physiological shock, illness, surgery, childbirth, severe stress, a nutritional deficit, pushes up to 30 to 50 percent of growing follicles prematurely into telogen. Around two to four months after the triggering event, those hairs shed simultaneously, which is why the shedding seems to come out of nowhere.

Acute telogen effluvium usually resolves on its own within three to six months once the systemic trigger is removed, because the follicles are fine and the cycle resets. The shed hairs are full length, the loss is diffuse across the entire scalp rather than patchy, and the regrowth shows as short hairs at the hairline. If shedding stays heavy beyond six months, or the loss is patchy rather than diffuse, get iron, thyroid, and vitamin D checked, because a cycle problem that does not reset is usually a medical problem, not a hair problem.

What breakage means, and how to stop it

Breakage is a mechanical failure of the hair shaft. Hair fibers are an outer cuticle of overlapping keratinized scales, an inner cortex that provides tensile strength and elasticity, and sometimes a central medulla. A virgin human hair fiber can typically stretch up to 30 percent of its dry length before snapping. Bleach, heat, friction, and chemical processing weaken that structure until normal handling, brushing, toweling, ponytails, is enough to snap it.

Breakage stops only when styling, heat, or chemical practices change. The fixes are unglamorous: stop heat styling for a few weeks, detangle from the ends upward with a wide-tooth comb, never rip through wet hair, and trim the frayed ends, because split ends travel up the shaft. Unlike shedding, breakage shows up as uneven lengths, flyaways, thinned ends, and localized patchy loss, and the pattern tells you where the damage is happening.

Frequently asked questions

How can I tell if my hair is shedding or breaking?

Look at the root end. Shed hairs are full length with a tiny white bulb, while broken hairs are short, uneven fragments with frayed or split ends and no bulb. Lay the fallen strands on a white sheet under good light: a bulb means shedding, no bulb means breakage.

How many hairs a day is normal to lose?

Fifty to 100 hairs a day is standard baseline turnover for a healthy scalp, according to clinical research published by the British Association of Dermatologists. At any time, roughly 85 to 90 percent of scalp hairs are in the growth phase and 10 to 15 percent are resting.

What causes telogen effluvium?

An acute physiological shock, illness, surgery, childbirth, severe stress, or a nutritional deficit, pushes up to 30 to 50 percent of growing follicles into the resting phase. Shedding starts two to four months after the trigger, and usually resolves within three to six months once the trigger is removed.

Can breakage and shedding happen at the same time?

Yes, and severe breakage and acute shedding often co-occur, which makes self-diagnosis harder. The bulb test separates them strand by strand: full-length hairs with bulbs are shedding, short fragments without bulbs are breakage, and the fixes are different for each.