If you see or smell this on your mattress, it has gone moldy — here’s what to do next

 A close up image of a mattress displaying a smattering of black dots, which is a sign that mold is present.
A close up image of a mattress displaying a smattering of black dots, which is a sign that mold is present.

Mold is present in approximately 70% of American homes, but it isn’t always easy to spot. Mold can negatively impact your health as well as disrupt your sleep, so it’s important to act quickly if you find mold growing on or around your bed. Which is why you might be wondering how to spot signs of mattress mold.

What is mattress mold?

Mold is an organic fungi made up of tiny organisms that lives in dark, damp environments and spreads by releasing spores into the air. On a mattress, mold has a musty smell and can look furry or 'powdery'.

Common characteristics of a moldy mattress include a musty smell and a smattering of furry or powdery spots which can be black, off-white or pink in color. Other indications of a moldy mattress include signs of mold elsewhere in your bedroom, as mold can spread rapidly, especially if your room is humid or your mattress has been exposed to moisture.

Investing in a natural latex or hypoallergenic mattress can help repel mold but no bed is completely immune to mold, Here we outline the signs of mattress mold and walk you through what to do next.

If after reading this you decide you need to buy a new bed, our official best mattress of 2024 guide contains our top recommendations for all sleepers – and we expect several of them to drop in price during the Presidents' Day mattress sales too, so now is a good time to buy.

3 signs that your mattress has gone moldy

1. It smells musty

Your nose might be the first thing to detect a moldy mattress. An unpleasant musty smell is a strong indication that your mattress is moldy. So, at the first unpleasant whiff, strip your bed and give your mattress a thorough inspection, looking deep into any folds of the fabric and on all sides.

2.  There are new, unexplained stains

Image shows black mold on a mattress and the corner of a scrubbing brush used to clean the mold
Image shows black mold on a mattress and the corner of a scrubbing brush used to clean the mold

Without a decent mattress protector, pee, sweat and spills leave yellow marks on your mattress. But any new unexplained discoloration, which could be off-white, pink, yellow, green, brown, or black (or a combination of all) in color, is another sign that your mattress is moldy.

3. There's a smattering of dark spots

If you remove your sheets to find swathes of dark-colored dots over your mattress, not only does your mattress have mold, the mold is already very established. Vivid dark spots that look like black, brown, green or purple paint splatters is one of the most common identifiers of mold. They could be fluffy, powdery or slimy in texture.

If you don't see them at first glance, look deep into the folds of any fabric and on the underside of your mattress. Mold thrives in dark and humid environments, so might not be immediately visible.

Other signs your mattress is moldy

There is mold elsewhere in your bedroom

If there is mold elsewhere in your bedroom, there’s a strong chance that mold could be lurking within your mattress, too. Mold is a fungus made up of tiny organisms that spreads by releasing airborne spores into the environment in the hope of finding somewhere dark and damp to land, increasing its spread.

So if there’s mold elsewhere in your bedroom, whether it’s growing on the walls or other soft furnishings, like the curtains or carpet, it’s a safe assumption that mold is growing in your mattress, too. Mold can begin to germinate and spread within 24 hours of encountering a moist, new environment, so you’ll need to act on the first sign.

You have unexplained illness

According to CDC guidelines, mold exposure can have adverse effects on your health, especially if the source of your mold is something that you’re laying on for upwards of eight hours per night. You might experience:

  • Frequent headaches

  • Nasal congestion

  • Sore throat

  • Coughing

  • Wheezing

A woman suffers from a headache after sleeping on a moldy mattress
A woman suffers from a headache after sleeping on a moldy mattress

The American Lung Association explains that mold exposure can worsen existing respiratory issues, such as asthma, as well as triggering allergic reactions. So it’s important to act fast when confronted with the above warning signs that your mattress is moldy.

Your sleep is disrupted

As well as impacting your health, mold can also disrupt your sleep. Studies show that the presence of mold within your home can cause insomnia, snoring and excessive daytime sleepiness. Additionally, mold can worsen allergy symptoms, so you may be kept awake by by difficulty breathing out of your nose.

How to remove mold from a mattress

If you’ve found mold growing on or within your mattress, your next question will likely be — how do I remove mold from my mattress? Depending on the severity of your mold problem, it is possible to remove mold from your mattress if caught early enough. Here’s how:

  • Remove and launder all bedding then thoroughly vacuum the mattress  

  • Clean the mold with an alcohol or hydrogen peroxide solution 

  • Allow the mattress to dry in direct sunlight  

Strip and launder all your bedding at 140° F (60° C), taking into account any care labels. Then thoroughly vacuum your mattress to lift any dust, as mold spores can live within dust particles.

When applying the cleaning solution, use circular motion to try to lift the mold but make sure you don’t oversaturate the area — especially if your mattress is memory foam, which can become damaged when exposed to water.

Once finished, allow your mattress to dry completely in direct sunlight and in front of an open window. Dressing your bed if your mattress is still damp could make your mold problem worse.

When to replace your moldy mattress

It's incredibly difficult to remove mold from your mattress entirely, especially if it's growing deep within the impenetrable layers of the mattress. Unfortunately, once this happens, your only real option is to replace your mattress. While this can be expensive, timing your purchase to coincide with major sale events like the upcoming Presidents' Day mattress sales means getting a new mattress at the lowest possible price.

To prevent mold from reinvading your sleep space, opt for a mattress with hypoallergenic properties or natural latex, which are both naturally mold-repellent. Here are our top two picks for anti-mold mattresses:

Saatva Classic Mattress: From $1,095 at Saatva
The Saatva Classic , which tops our best hybrid mattress guide is treated with a Guardin Botanical Antimicrobial formula. This stops the growth of bacteria, mold and mildew. For further detail into why that's important, check out our Saatva Classic mattress review .View Deal

Birch Natural mattress: From $1,599 at Birch by Helix
The Birch Natural mattress tops our best organic mattress guide, thanks to its inclusion of natural materials, including Talalay Latex. Latex is naturally mold-repellent, but can be pricey. However, a pre-Presidents' Day sale knocks 20% off its MRSP, which brings the price of a queen down to $2,599 from $3,248.80. View Deal