Quanto tempo deve ficar o bicarbonato no colchão?

Entre uma e duas horas chega para uma limpeza de rotina, com o quarto arejado. Se o colchão tiver cheiro a suor ou humidade, pode deixar até quatro horas antes de aspirar. Aspire depois com cuidado, até não restar pó.

O sol mata os ácaros do colchão?

A SPAIC considera a exposição direta ao sol de roupas, tapetes e colchão um método eficaz para diminuir o número de ácaros. Escolha um dia seco e areje as duas faces. Funciona melhor em conjunto com a aspiração e a lavagem a quente da roupa de cama.

Com que frequência devo aspirar o colchão?

A SPAIC recomenda aspirar o colchão pelo menos duas vezes por semana como medida de rotina, de preferência com filtro HEPA. Inclua as costuras, as laterais e, sempre que possível, o estrado.

Que doenças podem provocar os ácaros?

Segundo a SPAIC, a exposição às proteínas do corpo e aos excrementos dos ácaros pode causar doenças alérgicas, sobretudo respiratórias, como a rinite e a asma. Se os sintomas persistirem, um médico de família ou um imunoalergologista pode confirmar a alergia e indicar o tratamento.

Posso limpar o colchão com vapor?

Evite o vapor em nódoas de urina ou sangue, porque o calor fixa as proteínas no tecido. Para as nódoas, use água fria aplicada com pano e garanta sempre a secagem completa antes de fazer a cama.

Back to the journal

6 November 2026

Dust mites in the mattress: how to eliminate them and remove stains without damage

Any mattress with a few months of use has dust mites, and no cleaning makes them disappear completely. What you can do is significantly reduce their population and, above all, the allergens they leave behind: wash bed linens at 60 °C every week, vacuum the mattress on both sides with a HEPA filter, air out the room every morning, and keep humidity below 50%. In this guide, we show the complete method, what bicarbonate actually does, the routine that prevents the return of dust mites, and how to remove blood, urine, and sweat stains without soaking the foam.

In summary

The mattress is the main source of dust mites in the home: the problem is not the bite (they do not bite), but the excrement and debris that cause allergies.
No single measure solves the problem: hot washing, frequent vacuuming, anti-mite covers, and humidity below 50% work together.
Bicarbonate refreshes and absorbs moisture and odors, but does not eliminate the mites settled inside the filling.
For stains, the rule is the same for all: little water, applied with a cloth, and complete drying before making the bed.
Blood comes out with cold water; urine requires neutralization and never steam, because heat sets the stain and the smell.

Index

What are dust mites and why do they choose the mattress
Signs that dust mites are affecting your sleep
How to eliminate dust mites from the mattress, step by step
The routine that prevents the return of dust mites
Humidity: the factor that weighs most in a house in Lisbon
How to remove stains from the mattress according to type
Common mistakes that ruin the mattress
Our perspective
When the whole house needs a deep clean
Frequently asked questions
Sources

What are dust mites and why do they choose the mattress

House dust mites are microscopic animals that live in dust and settle in carpets, blankets, cushions, mattresses, rugs, and plush toys. According to the Portuguese Society of Allergology and Clinical Immunology, they prefer humid places and mild temperatures, feeding mainly on human skin flakes, and the allergy they cause lasts all year, with more intensity in autumn and winter.

The bed gathers everything they seek: body heat, moisture from sweat, and a constant supply of shed skin. It is no surprise that the same society, in the document Domestic Allergens, points to the mattress as the main source of dust mites in the home, with about 10 million living in a single mattress.

They also do not concentrate where you might think. A study from Unicamp in Brazil, reported by Revista Pesquisa FAPESP, counted 950 mites per gram of dust on the side of the mattress in contact with the body and 3,900 near the bed frame. The same team indicated that about a hundred mites per gram are enough to sensitize the immune system and that, from 500, allergic crises occur. That is why vacuuming only the top side leaves the job half done.

Do dust mites bite?

No. The MSD Manual clarifies that house dust mites do not bite: they feed on skin cells that remain in cushions, mattresses, and on the floor. What affects health are the allergens present in their exoskeleton and feces, to which many people develop respiratory hypersensitivity. If you wake up with marks on your skin, the cause is something else and deserves to be looked at separately.

Signs that dust mites are affecting your sleep

The most common signs appear in bed or right after waking up: sneezing fits, a stuffy or runny nose, irritated eyes, and nighttime cough. For those with asthma, exposure can worsen shortness of breath and the feeling of tightness in the chest.

If sneezing, congestion, or nighttime cough persist even after adopting the care in this guide, the right step is to talk to your family doctor or an immunoallergologist, who can confirm if there is an allergy to dust mites and suggest treatment, as noted by idealista/news. In children with persistent cough or wheezing, consult the pediatrician before changing the routine on your own.

How to eliminate dust mites from the mattress, step by step

Set aside a dry morning, preferably sunny. The method below combines the recommendations from SPAIC and the Portuguese Asthma Association with a step-by-step cleaning process without excessive water.

Remove all bed linens and wash them in hot water. Sheets, pillowcases, and mattress covers go into the machine at 60 °C, whenever the label allows. SPAIC recommends temperatures above 55 °C, and APA reminds that the hot program is more effective than the cold one.
Air out the mattress and the room. Open the windows and, if possible, place the mattress in the sun: direct sunlight exposure of clothes, rugs, and the mattress is one of the methods that SPAIC considers effective for reducing dust mites.
Vacuum both sides, seams, and edges. Use the upholstery nozzle and a vacuum cleaner with a HEPA filter, which retains fine particles instead of returning them to the air. Focus on the edges and seams, where dust accumulates.
Also vacuum the bed frame and the floor under the bed. APA includes the floor, mattress, and bed frame in the room cleaning. Remember the numbers from the Brazilian study: the area near the bed frame is the most loaded.
Spread a thin layer of baking soda. Let it act for one to two hours with the room aired out, as described in the step-by-step from idealista/news, or up to four hours if the mattress has an odor.
Vacuum again, slowly. Pass the vacuum cleaner in overlapping strips until no white powder remains.
Treat the stains last, with little water. Dampen a cloth, never the mattress, and work from the outside in (see the stains further down).
Let it dry completely before making the bed. Window open, fan or hairdryer on cool or warm air, never hot. The mattress must be dry to the touch and inside.

For wool cushions, blankets, and plush toys that cannot withstand hot washing, SPAIC suggests another route: 24 hours in the freezer and then washing.

Does bicarbonate kill dust mites?

It helps, but it's not enough on its own. Some articles present it as a natural biocide that dries out dust mites, but a more cautious analysis, published by Infobae, concludes that bicarbonate and vacuuming reduce surface dirt and refresh the mattress, without eliminating the mites settled inside the foam or filling.

Use it for what it does well: absorbs moisture and odors and makes the surface less inviting. The deep cleaning continues to be done by hot water in bed linens, regular vacuuming, and humidity control.

The routine that prevents the return of dust mites

SPAIC is clear on one point: reducing domestic allergens cannot be achieved with a single measure, only with several at the same time. This is the routine that results from the recommendations of Portuguese entities:

Task	Frequency	Why it works
Wash sheets and pillowcases at 60 °C	Weekly (APA advises changing 1 to 2 times a week)	Heat reduces mites and allergens in textiles
Vacuum the room and mattress with a HEPA filter	At least 2 times a week	Removes dust, skin, and feces before they accumulate
Air out the room and leave the bed open	Every morning	Releases moisture from the night
Make the bed only later	Daily	Open sheets dry and cool down
Anti-mite covers with a zip all around	Permanent, washed with bed linens	Create a barrier between the mattress and the body
Wash duvets and washable pillows	Monthly or seasonal	The filling accumulates mites like the mattress
Review textiles in the room	Once per season	Fewer thick rugs, decorative cushions, and plush toys

Regarding materials, the APA prefers synthetic bed linens (polyester is better than cotton), washable foam cushions, and avoiding flannel sheets and fluffy blankets in homes of those with asthma or allergies.

If you want to see where these tasks fit into the rest of the house, our domestic cleaning calendar organizes the frequency for each room.

Humidity: the factor that weighs most in a house in Lisbon

Dust mites need humidity to survive, and many houses in Lisbon, especially the older ones and those near the river, spend winter with humid air and closed windows. This is where the battle is won or lost.

SPAIC recommends keeping relative humidity below 50% to stop the growth of dust mites and fungi. Air conditioning is the most effective way, as long as the filters are cleaned regularly, and dehumidifiers help in some situations. The Portuguese Lung Foundation advises the same limit of 50% for those with dust mite allergies, according to idealista/news.

In practice:

buy a simple hygrometer and place it in the room, away from the window;
air out for ten minutes every morning, even in winter;
do not dry clothes in the room;
if the value stays above 50% persistently, turn on the dehumidifier during the day and empty the tank frequently.

How to remove stains from the mattress according to type

Each stain requires its own treatment, but there are three common rules: act quickly, absorb before cleaning, and never pour liquid directly onto the mattress. Water that enters the foam takes days to come out and creates the humid environment that dust mites and mold seek.

Stain	What to use	What to avoid
Fresh blood	Cold water and a clean cloth	Hot water, which sets the stain
Dried blood or yellowed stains	Baking soda paste with 10-volume hydrogen peroxide	Scrubbing hard
Urine	Absorbent paper, diluted vinegar, enzymatic product	Steam and heat
Sweat and odors	Dry bicarbonate, several hours	Perfumes that mask the smell

Blood stains

Remove the excess with paper or a dry cloth, pressing without rubbing. Then, dampen a cloth in cold water and work the stain from the outside in, to avoid spreading it. Finish only with cold water to remove residues and absorb moisture with another dry cloth, as recommended by BedLab. Hot water coagulates the proteins in the blood and binds the stain to the fabric.

For already dried blood, the baking soda and hydrogen peroxide paste described below is the best bet.

Yellowed, sweat, and old stains

Dry bicarbonate treats odors but does not whiten. For visible stains, Correio Braziliense describes a baking soda paste with 10-volume hydrogen peroxide, applied only on the stain, left to dry until it turns to powder, and then vacuumed. Hydrogen peroxide can bleach some fabrics: test first in a hidden area of the mattress fabric and do not mix it with other cleaning products.

Urine and the lingering smell

With urine, timing is everything. Absorb immediately with kitchen paper or towels, pressing. Then neutralize with one part cleaning vinegar to two parts water, applied with a cloth, and use an enzymatic product that breaks down the uric acid crystals responsible for the smell that returns days later. Dry with the window open and a fan pointed at the bed, and do not make the bed while the mattress is damp, as explained by Achaté.

Two mistakes make everything worse: scrubbing hard, which spreads the urine and pushes it in, and using steam, whose heat sets the proteins in the urine to the fabric and makes the smell permanent.

If you are a tenant and are moving out, treat the stains on the mattress of the house in advance: complete drying takes time, and a landlord's mattress with marks or odor is a frequent cause of dispute. Our guide on cleaning to recover the deposit includes the rest of the list.

Common mistakes that ruin the mattress

Soaking the mattress. The foam retains water, drying takes time, and moisture brings mold and dust mites back.
Drying with hot air. Damages some materials and sets organic stains. Use cool or warm air.
Making the bed immediately. Sheets and duvet on top trap moisture. Wait until the mattress is dry to the touch.
Vacuuming only the top side. Dust mites also concentrate near the bed frame, and seams are their hiding place.
Relying on a single measure. Without hot washing and controlled humidity, any mattress cleaning lasts little.
Mixing products. Vinegar, bleach, and hydrogen peroxide do not mix. Use one at a time and rinse with a damp cloth between them.

Our perspective

Those who call us about allergies often start with the mattress, and they are right. But the mattress is just one part of the room. The dust that feeds the dust mites is also in the baseboards, under the bed, in the curtains, in decorative cushions, and on the shelves, and it returns to the bed if it stays there.

That’s why we work with detailed checklists, room by room, and with fixed teams whenever possible. The same person knows your home, knows where the dust accumulates, and does not skip steps from one visit to the next. It is consistency, more than a heroic cleaning once in a while, that keeps the allergen load low.

For those with little time, the most sensible combination is a deep clean to reset the room and then regular maintenance, with bed linens treated as an extra. This way, the routine that SPAIC recommends no longer depends on the week you had.

Flaws

When the whole house needs a deep clean

If you live in Lisbon and want to start from scratch, our Signature Deep Clean takes care of the house from top to bottom, with a transparent checklist and quality control, and you can add extras like laundry and bed linens or upholstery cleaning.

Cleaningpoint

After that, the professional home cleaning maintains the standard with the same team whenever possible and support in several languages. See what we clean in each room or book a cleaning directly.

Frequently asked questions

How long should bicarbonate stay on the mattress?

Between one and two hours is enough for a routine cleaning, with the room aired out. If the mattress has a smell of sweat or humidity, you can leave it for up to four hours before vacuuming. Then vacuum carefully until no powder remains.

Does the sun kill dust mites in the mattress?

SPAIC considers direct sunlight exposure of clothes, rugs, and the mattress an effective method for reducing the number of dust mites. Choose a dry day and air both sides. It works best in conjunction with vacuuming and hot washing of bed linens.

How often should I vacuum the mattress?

SPAIC recommends vacuuming the mattress at least twice a week as a routine measure, preferably with a HEPA filter. Include seams, edges, and, whenever possible, the bed frame.

What diseases can dust mites cause?

According to SPAIC, exposure to body proteins and dust mite feces can cause allergic diseases, especially respiratory ones, such as rhinitis and asthma. If symptoms persist, a family doctor or an immunoallergologist can confirm the allergy and suggest treatment.

Can I clean the mattress with steam?

Avoid steam on urine or blood stains, as heat sets the proteins in the fabric. For stains, use cold water applied with a cloth and always ensure complete drying before making the bed.