Incontinence pads and period pads: what’s the difference?

An incontinence pad (sometimes called a bladder pad) and a period pad can look almost the same in the hand. Most have the same layers, the same shape and a strip of adhesive on the back. The difference is the job. Researchers describe the two liquids as different in “composition, viscosity, and pH”, and they arrive at different speeds. This Column is for everyone who has periods, and for anyone who has picked up one box while thinking about the other.

How each one is built

Researchers and the industry describe disposable incontinence pads and disposable period pads in the same way, whichever liquid each is for. There is a top layer against the skin. Under it sits a layer that moves liquid downward. Then comes the absorbent core. Below the core is a backsheet, a thin film that keeps liquid from passing through. Adhesive holds each one in place.

The core is usually wood-pulp fibre. The researchers list “wood pulp fluff, cellulosic card wadding, and superabsorbent polymers”. Superabsorbent polymer (SAP) is a granule that locks liquid in and holds it under pressure.

Sources differ on what is inside a period pad. An Australian continence body lists period-pad material as “cellulose or fibre”. An industry body describes period pad cores as “Cellulosic or/and synthetic fibres with or without a super absorbent polymer (SAP)”. Clinicians writing in 2023 say “Disposable menstrual pads are made of cotton combined with superabsorbent polymers”. Cores vary by product. In one UK lab study, some of the period pads tested had no SAP. The maker’s own list of materials is the place to check.

Two liquids, two speeds

A continence body describes urine as “thin, fast-flowing” and period flow as “thick, slower-flowing blood”.

Timing differs too. Researchers note that period fluid is released “gradually over several days rather than in discrete events”. For that reason, they write, period pads “do not need as high an absorption rate as incontinence pads”. A bladder leak can arrive as a sudden gush. For scale, the same researchers give urine flow during ordinary urination as peaking at about 20 to 30 mL per second. That figure describes urination in general, not a leak.

Volume is the third difference. The Australian continence body describes incontinence pads, which it calls “continence pads”, as built for “very high” absorbency and “large amounts”. A whole period, according to Canada’s SOGC, is about 30 to 50 mL, or 2 to 3 tablespoons. The Australian body says that “for most women, menstrual loss is less than 80mls each period cycle”. Sources give different ranges, so each figure carries its source.

A note on words: the sources we cite here say “women”. We keep researchers’ words so we report their findings accurately. The Reading Room is for everyone who menstruates.

What each one is designed to do

Same shape. Different job. The Australian continence body describes incontinence pads as designed to “reduce odour” and, in its table, as a product that “Keeps skin drier” when the liquid is urine. The same body says that a period pad used for urine leaves the skin “wetter” and can bring “leakage and odour”. Its table also lists “Poor absorption of blood” as the risk when an incontinence pad is used for a period.

That is a description of each product used for a liquid it was not designed for. It is not a verdict on either product. The Editor reports it in the source’s words and stops there.

Why people reach across the aisle

People do use one for the other. Researchers note that “menstrual pads are used to manage incontinence”. In forums, readers describe the reverse: incontinence pads, briefs or bed pads on heavy period nights and in the weeks after a birth.

On heavy nights. A bigger size is one reason readers pick up an incontinence pad. If the reason is that your period has become heavier than a period pad can hold, the section “When to talk to someone” is for you.

After a birth. The bleeding after birth is called lochia. A review of 18 studies found that the average reported duration ranged from 24 to 36 days, with wide variation. HealthLink BC’s advice is plain: “Use sanitary pads until you stop bleeding… Do not use tampons until your doctor says it’s okay.” It does not say whether it means period pads or incontinence pads. HealthLink BC says to call your doctor now or seek immediate medical care if you are “soaking through one or more pads in an hour”. In an emergency, call 9-1-1.

Bladder leaks after a birth are common too. An Australian continence body reports that “One in 3 women who have had a baby experience some loss of bladder control”. That is an Australian figure. The Editor found no Canadian one. More broadly, an international review found that most population studies put any urinary incontinence in women at 25 to 45 percent, rising with age.

In perimenopause. According to the SOGC, the years before menopause may bring “skipped periods, shorter cycles, or unusually heavy or light bleeding”. This stage can last 4 to 8 years, sometimes 10 or more. Some readers describe heavy days and bladder leaks arriving in the same years, and a cupboard holding both boxes.

What the box tells you, and what it doesn’t

In Canada, the two kinds of product sit under different rules. Employment and Social Development Canada puts it this way: “Menstrual pads aren’t medical devices or regulated in Canada.” Tampons and menstrual cups, by contrast, are listed as Class II medical devices in Health Canada’s device keyword index.

Tampons have standardised absorbency labels in Canada. No such standard was found for incontinence pads or period pads. So “regular”, “overnight” and the number of drops on a box are each maker’s own scale. A drop count on one box is not a shared measure, so it may not match another maker’s.

When to talk to someone

A bigger size can answer a question about fit. It cannot answer a question about your body.

If needing more than usual is the reason for an incontinence pad on period days, look at the SOGC’s signs of heavy menstrual bleeding. Among them, in its words: “Needing to wear more than one pad at a time”; “Needing to change pads or tampons during the night”; soaking through “one or more tampons or pads every hour for several hours in a row”; clots “as big as a quarter or larger”; and bleeding “more than 7 days”. These are signs to discuss with a provider, not a test to score yourself on.

For leaks of urine, HealthLink BC says: “Urinary incontinence isn’t an inevitable result of aging. Most women who have it can be helped or cured.” The Canadian Continence Foundation says a pelvic health physiotherapist “often provides first-line, evidence-based treatment” for bladder leaks.

If your periods are very heavy, very painful or have changed, or if leaks are part of your day, that is a conversation for a healthcare provider, not for a Column. This is where the Editor stops and a healthcare provider begins.

What this is not

This Column described how incontinence pads and period pads are built and what their makers and sources say they are for. It did not compare brands. It did not tell you which one to wear. It makes no claim that any period pad or incontinence pad treats bladder leaks; neither is a treatment. For treatment, “When to talk to someone” points to people who can help.