When I was new in the field of wound care, I was eager to learn everything I could. I recall watching one of my clinical instructors closely, someone I deeply admired. She was teaching a group of newly hired nurses in a hospital. Some of them had decades of experience, while others were just beginning their careers, but we all listened intently. That day, she taught us something simple, yet unforgettable. She placed two different underpads on a table. These are the pads many people use to protect furniture or bedding for those managing incontinence. One was a traditional chux pad, and the other was what she referred to as an advanced moisture-management underpad.
She poured the same amount of water on each pad. Then she asked us one by one to place a hand on both, calling this the hand test. And I’ll never forget what I felt. One pad mainly stayed dry to the touch. The other was cold, damp, and uncomfortable; my hand was soaking wet. My instructor paused and then quietly asked: “How would you feel if you were the one sitting on that wet pad?” Her words hung in the air. We all fell silent. In that moment, I understood something that was essential, that is not in any textbook or a policy manual, comfort is not a luxury and dignity is not optional. And small choices that we make in caring for someone with incontinence or living with it ourselves can make a big difference.
Underpads (often referred to as chux) are a familiar sight in homes and healthcare settings. They line beds, recliners, and wheelchairs to protect surfaces from moisture. But not all underpads perform the same way. Today, we have better options, advanced moisture-management underpads that do much more than catch liquid. They protect the skin by pulling moisture away and locking it deep inside the pad. Both types of underpads discussed in this article are disposable, but one outshines the other by far.
Understanding Traditional “Chux” Underpads
Traditional disposable underpads, often called “chux”, are made of three layers:
- A soft top layer touches the skin.
- A middle absorbent layer (fluff pulp) made of cellulose fibers.
- A waterproof plastic backing protects furniture or bedding underneath.
These pads are inexpensive and straightforward. They absorb a small amount of urine, then rely on quick changing to prevent wetness from sitting against the skin. Traditional chux with plastic backing should not be used on low air loss beds, as they can be harmful by blocking therapeutic airflow, trapping heat and moisture, and reducing the effectiveness of the low air loss mattress’s ability to dissipate heat and moisture. They also rip or tear under body weight, bunch or wrinkle, increasing friction and shear (which can cause skin breakdown), and leak when the surface integrity is compromised.
Common traditional brands
Many low-cost “chux” underpads are sold under generic names (hospital-grade or store brand). Examples include Dynarex Disposable Underpads or McKesson Classic Fluff Underpads. These are often labeled “standard” or “basic absorbency.”
How they work
When moisture hits the pad, it spreads across the fluff layer. Because these pads usually lack modern absorbent materials, liquid may remain near the surface, especially when a person moves or applies pressure to the pad. This can leave the skin damp and prone to irritation.
For light, occasional leakage, traditional chux can help protect furniture. But for regular or heavy incontinence, they are not enough to keep the skin dry.
What Are Advanced Moisture-Management Underpads?
Advanced moisture-management underpads look similar at first glance but are engineered very differently. These products contain superabsorbent polymers (SAPs), tiny gel particles that pull in and hold liquid many times their own weight.
How they work
- Fast absorption: Fluid passes through the top layer almost instantly.
- Lock-away technology: The SAP core traps liquid as a gel so it can’t flow back to the surface.
- Even distribution: Engineered channels spread fluid evenly, preventing “pooling.”
- Drier surface: The topsheet stays noticeably drier against the skin.
In my experience, the Medline Ultrasorbs product line is one of the better advanced moisture-management underpads. They come in 4 product lines:
- Medline Ultrasorbs (formerly Extrasorbs AP): Everyday absorbency, recommended for use with low air loss therapy beds, no repositioning.
- Medline Ultrasorbs Advanced Premium (formerly Extrasorbs and Ultrasorbs): Everyday absorbency,recommended for use with low air loss therapy beds, 300–375 lbs. repositioning capacity.
- Medline Ultrasorbs Advanced+ Premium (formerly Ultrasorbs ES): 20% extended core coverage,recommended for use with low air loss therapy beds, 300–375 lbs. repositioning capacity.
- Medline Ultrasorbs Advanced Complete (formerly Therasorbs): Fastest absorbency,recommended for use with low air loss therapy beds, 400 lbs. repositioning capacity.
Some advanced moisture-management underpads help caregivers safely move, turn, or reposition a person in bed without tearing, bunching, or compromising the pad’s absorbent or protective performance. The repositioning capacity is the weight limit at which you can perform this without damaging the underpad.
As with any medical product, it is important to follow the manufacturer’s instructions and to recognize that different products work better for some people than others.
Each uses advanced polymer cores and multi-layer construction to manage moisture more effectively than standard fluff underpads.
Absorbency: How Much Liquid Can Each Hold?
Absorbency varies widely by brand and product size, but scientific testing gives us a general idea.
Traditional “Chux” Pads
- Typically hold 300–500 mL of liquid (about 1–2 cups).
- Liquid often remains near the surface, especially under body pressure.
- Should be replaced promptly after each episode of incontinence.
Advanced Moisture-Management Underpads
- Can retain up to 1,000–1,500 mL or more (about 4–6 cups) depending on size and design.
- Use SAPs that gel and immobilize liquid — preventing it from rewetting the skin.
- Maintain a drier topsheet even after multiple voids.
In practical terms, an advanced underpad can hold two to three times more fluid while keeping the skin much drier than a standard chux pad.
Comparing Traditional vs. Advanced Moisture Mangement Underpads
| Traditional “Chux” Underpads | Advanced Moisture-Management Underpads | |
| Absorbent Core | Fluff pulp (cellulose) only | Superabsorbent polymer, engineered core |
| Surface Wetness | Often remains damp | Rapidly dries, stays drier for hours |
| Fluid Capacity | 300–500 mL typical | Higher than 1,000 mL (varies by size/type) |
| Odor Control | Limited | Typically traps odor |
| Leak Prevention | May leak under pressure | Distributes fluid evenly; locks it in |
| Skin Protection | Moderate; requires frequent changing | Superior; reduces risk of IAD/MASD |
| Cost per Pad | Low | Higher initial cost, but fewer needed |
Why This Matters for Skin Health
Urine or stool disrupts the skin’s natural barrier when in contact with the skin. Prolonged moisture leads to softening (maceration), irritation, and, in some cases, painful breakdown. This condition is called incontinence-associated dermatitis (IAD), a type of moisture-associated skin damage (MASD).
IAD is common and preventable. Keeping skin dry and reducing contact with irritants are crucial preventative steps. Advanced moisture management underpads have shown to significantly reduce skin breakdown and improve patient comfort compared to traditional underpads.
Why Advanced Underpads Are the Better Choice
Healthier Skin
Drier skin is associated with fewer pressure injuries and less dermatitis. Advanced moisture management underpads minimize moisture contact, helping prevent pain, redness, and infection. Preventing prolonged exposure to urine and feces is the most critical step in protecting skin integrity.
More Comfort and Dignity
Staying dry longer means fewer interruptions at night and greater comfort. For caregivers, this also means fewer linen changes and a calmer routine, reducing stress for both the person and the caregiver.
Better Value Over Time
While advanced moisture management pads cost more per piece, they often reduce total underpad use and laundry loads. They also reduce the risk of costly complications, such as skin breakdown or infection.
Improved Odor and Hygiene
By trapping moisture and bacteria inside the core, advanced underpads help reduce odor and keep the caregiving environment more pleasant.
Clinically Recommended
Wound-care and continence-care guidelines recommend highly absorbent, quick-drying materials for patients at risk of skin breakdown, exactly what advanced underpads provide.
When to Use Advanced Moisture-Management Underpads
You don’t need to use the most advanced pad in every situation, but they’re especially beneficial when:
- The person experiences heavy or frequent leakage (especially overnight).
- Skin is already fragile or irritated.
- The person is bed- or chair-bound and sits for long periods.
- Nighttime sleep interruptions cause fatigue or distress.
- Laundry or linen changes are challenging to manage.
Even if you use reusable or standard underpads during the day, switching to advanced underpads at night can make a noticeable difference in comfort and skin health.
Caregiver Tips for Underpad Use
- Inspect skin daily looking for signs of redness, softness, or soreness, early indicators of moisture damage.
- Change underpads immediately when wet or soiled, as all underpads have a limit, and store underpads in a dry, clean area to protect absorbency.
- Use a gentle, pH-balanced cleanser and pat skin dry.
- Apply a moisture barrier cream.
- Combine with breathable incontinence briefs for complete protection.
- Ask for samples as many suppliers will let you try a few types before committing to a case.