What Could I Be Allergic to in My House? Indoor Allergens 101

May 10, 2022

What Could I Be Allergic to in My House? Indoor Allergens 101

6 minute read

Seasonal pollen allergies are definitely something to sneeze about, and they can be enough to make you want to shelter inside for the entirety of the spring and summer.

But if the sneezing and wheezing don’t stop just because you shut yourself inside, there might be some hidden triggers unbeknownst to you within your humble abode.

Indoor allergies have nearly identical symptoms to outdoor allergies, but in many cases, they can be even more difficult to identify the source of.

Let’s take a look at everything you need to know about indoor allergens so you can finally get some relief and avoid exposure.

What Are Allergies?

Unlike a cold or the flu which both have pretty clear causes, allergies are a bit more tricky because your coughing and watery eyes might occur from just sitting in your bedroom.

Allergies are an immune response that occurs when your body reacts to a foreign substance, like pollen.

The main difference between an allergy and a cold or flu is that the causes of allergies are not actually harmful to your health. Pollen and dust mites, for instance, are common allergens that do not pose a health risk, though your body still perceives them as dangerous.

In essence, the symptoms you feel are your body’s way of flushing out these harmful substances so they stop bothering you.

So why do only certain substances cause allergy symptoms?

IgE antibodies, or immunoglobulin E, are produced by the immune system. If you have an allergy, specific forms of these antibodies travel to cells and release chemicals, eliciting an allergic reaction. Each type of IgE antibody has a specific “radar” for each type of allergen, which is why certain people are only allergic to certain things.

These antibodies are what cause those familiar yet nagging symptoms like an itchy throat, cough, stuffy nose, and more.

What Are Common Indoor Allergens?

There might be more triggers hiding inside of your home than you think. Let’s take a look at the most common, as well as some ways that you can try to cut down on your symptoms for each one.

Dust Mites

Dust mites are tiny bugs that live in house dust. That’s right — we said tiny bugs.

The good news is that these bugs are so tiny that you can’t even see them with the human eye.

But just because they’re small doesn’t mean they’re not mighty. Dust mites are the most common trigger of year-round allergy and asthma, and they exist on every single continent except for Antarctica. You’ll probably never be able to get rid of them from your home completely, but there are some ways you can try to dwindle them down.

Dust mites thrive in humidity levels between 70 and 80%, meaning that cutting down on the humidity in your home is extra important. You can do this by getting a dehumidifier to keep the relative humidity in your home around 45%.

Additionally, you can get rid of dust mites through frequent cleaning. Dust your surfaces, and be sure to vacuum carpets and upholstered furniture frequently.

We also recommend washing your bed sheets and pillows at least once every two weeks in hot water to kill dust mites and keep your sleeping space clear of triggers. Side note: don’t air dry them outside, as this can cause outdoor pollen to stick.

Pet Dander

There’s nothing better than cuddling up with your dog or cat on the couch. And while they mean no harm, they might also be one of the main reasons for your allergy symptoms. Pet dander is another common indoor allergy trigger.

It’s not an animal’s fur itself that causes allergies — it’s the skin cells that they shed.

Often, these cells stick to the fur, which easily floats through the air and makes you more susceptible to the symptoms. Dander can also be found in urine, saliva, and sweat from an animal.

Pet dander and saliva can stick to clothes and surfaces, like your carpets, curtains, furniture, and bedding.

One solution to counteract pet allergies is getting a “hypoallergenic” cat or dog. While there’s no such thing as an animal that is entirely hypoallergenic, these animals tend to have less fur and are less likely to shed their dander throughout your home. Some animals also do not produce the same proteins that usually contribute to pet dander allergies.

Additionally, brush your pet often to remove their hair before it can float through the air and affect your symptoms. Plus, this makes it easier for you to clean carpets and furniture.

You may also want to consider getting a HEPA filter or high-efficiency particulate air filter, which works to remove at least 99.97% of dust, pollen, bacteria, and other airborne particles (like pet dander) from the air. Just be sure to clean the air filter frequently.


Mold is another common allergy trigger, and while the green spots on that month-old loaf of bread probably won’t taste too good, that’s not necessarily the type of mold that’s causing you to wheeze and sneeze.

Mold is a type of fungus that reproduces through mold spores, which travel through the air. Some spores spread through windy, dry conditions outside. But inside, the main way these particles spread is through water particles in high humidity.

Fungi thrive in damp and warm environments, like bathrooms, basements, or attics, but they can grow anywhere at any time of the year, making this type of allergen particularly elusive.

Mold spores can trigger the symptoms of hay fever and asthma. You can try to cut down on the symptoms by preventing mold from spreading in the first place.

One of the best combatants against mold growth is reducing the humidity in your home. Since warm and damp environments are what lead to fungal growth, using a dehumidifier in problem areas like your bathroom, crawlspaces, or in your basement can be extremely helpful.

Additionally, running your air conditioning unit can help keep your living space more comfortable as well as remove moisture from the air. If you don’t have a central unit, you can use window air conditioners. Just be sure to replace the filter often.


Even if cockroaches weren’t an allergen, you probably wouldn’t want them in your home.

But considering they can gross you out and cause you to suffer, you probably want to take the necessary steps to avoid their wrath.

Cockroaches, like most indoor allergens, love warm and humid environments — especially where food is available. This makes your cupboards and any place in your kitchen their favorite place to be.

The thing is, cockroaches themselves aren’t necessarily the allergens themselves. The issue arises when they die. Since they don’t usually die in plain sight, their bodies break apart and dry up, becoming a part of house dust that you can breathe in.

To prevent these critters from inhabiting your home, cover all of your trash can lids tightly and store food in airtight containers. This includes food kept in cabinets and on counters. Additionally, do not leave dirty dishes in the sink, which can attract them easily.

Avoid leaving pet food out in the open, and try to dehumidify areas of your home that are high in moisture. Fix leaky pipes underneath sinks and ensure that your food within cupboards and other spaces in the kitchen is sealed tightly so roaches can’t sneak in.

What Are the Signs and Symptoms of Indoor Allergies?

The symptoms of indoor allergies look very similar to the symptoms of outdoor seasonal allergies. In most cases, they’ll present themselves as the following:

  • Itchy, stuffy nose
  • Sneezing
  • Nasal congestion
  • Coughing
  • Itchy, watery eyes
  • Tightness in the chest
  • Headaches
  • Difficulty breathing or wheezing, especially if you have asthma

How Do You Test for Indoor Allergies?

One of the tricky things about indoor allergens is that since the symptoms look the same for all of them, it can be impossible to know exactly what’s triggering them. This is why it’s important to get an allergy test to literally and metaphorically help clear the air.

There are a few options for allergy tests that all have their benefits and drawbacks.

Skin Prick Test

The golden standard diagnostic tool is the allergy skin test or prick test. This is done by an allergist in their office.

With a skin prick test, an allergist will use a tiny needle to prick the surface of your skin. After that, they will place tiny droplets of suspected allergens onto the surface to see how your skin reacts. If a tiny bump, called a wheal, forms, it is likely because you are allergic to that substance.

To ensure that your skin is reacting normally, the allergist will also apply histamine and saline to the skin as control tests. Most people react to histamine, so if you don’t react to it, you might not reveal a true allergy, even if you have one.

Conversely, most people are not allergic to saline, meaning that if your skin bumps up from it, you may have super sensitive skin.

Blood Test

The other most common type of allergy test is the blood test. The main benefit of this test is that a singular blood sample can be used to test for multiple allergens at one time, rather than the need for multiple skin pricks to test for each individual antibody.

Blood tests measure the amount of specific IgE antibodies in your bloodstream for a specific allergen. The more antibodies you have, the more likely you will have a severe reaction.

While you used to need to go into an allergist’s office to get an allergy blood test, this is no longer necessary.

You can do your blood test right from the comfort of your own home with Cleared’s at-home allergy testing kit. This kit tests for 40 common indoor and outdoor allergens so you can remove all the guesswork and finally understand what’s causing your symptoms.

How Can You Treat Indoor Allergies?

While taking an allergy test to understand your triggers and the proper preventative measures is important, it’s not always possible to avoid indoor allergies. For that reason, it’s important to take some necessary steps towards treating them after the symptoms have arisen.

Antihistamine Medications

One of the chemicals that is released by your immune system when confronted with an allergen is something called histamine. Histamine is responsible for causing most of the symptoms that are associated with an allergic reaction.

As their name implies, antihistamines work to block the effects of histamines on the body, therefore alleviating the symptoms. They can be taken after you start feeling allergy symptoms, but you can also take them before you feel symptoms as a preventative measure.

There are a few different types of antihistamines that all have specific benefits. Oral antihistamines are commonly used because they tend to alleviate symptoms throughout the entire body. However, nasal sprays are commonly used to counteract congestion, as they can reduce swollen blood vessels in the nostrils and make it easier for mucus to flow.

There are even eye drop antihistamines specifically targeted at itchy, red, watery eyes and anti-inflammatory medications aimed at individuals who may have respiratory issues like difficulty breathing.

With Cleared, you can get generic antihistamine medications for some of the lowest prices on the market.

Browse our selection to pick your favorites, or take your free allergy consultation to see if your online allergist can prescribe prescription-strength antihistamines instead.


Antihistamines are great for bringing fast-acting relief to the toughest allergy symptoms. However, they don’t actually cure the underlying conditions surrounding them. This is where allergy immunotherapy can come in and save the day.

Allergy immunotherapy, or AIT, is a way to treat allergies so you are less affected by them in general. It involves slowly and gradually exposing your immune system to small amounts of an allergen at a time to help you build up a tolerance.

AIT is typically administered in the form of allergy shots, but Cleared has an even easier method. It's called sublingual immunotherapy (SLIT), and all you need to do is place an immunotherapy tablet under your tongue and wait for it to dissolve. You’ll do this over a specified period of time until you start to gain a tolerance to the allergen.

SLIT reduces allergy symptoms by nearly 50% after just six months — no antihistamines required. We’ve got immunotherapy for dust mite allergies and outdoor triggers like grass or ragweed pollen. Take our quiz today to see if this revolutionary treatment might be the right option for you.

Home Remedies

Especially for more mild instances of allergy symptoms, some home remedies might be able to bring you the relief that you need, or may offer additional relief when used alongside medication.

If you’re experiencing itchy eyes, a cold compress might do the trick. Wet a washcloth with cold water and wring it out until it is damp. Then lay it over your eyes and relax for about 20 to 30 minutes. This can constrict the blood vessels in and around your eyes to reduce the itch-causing inflammation.

If a dry, itchy throat is what’s got you down, you can try drinking hot tea with some honey to soothe the irritation. The warmth from the tea may also work overtime to relieve nasal congestion, too.

In Conclusion

Your house is supposed to be a safe haven from the dangerous outside world. But if you’re an allergy sufferer, your house might be even more dangerous than outside.

Allergies are caused by a faulty immune system response in which your body perceives a foreign substance as a threat. This causes a release of chemicals that can lead to allergy symptoms.

The most common indoor allergens include dust mites, pet dander, mold, and cockroaches. All of them cause the same symptoms, like runny nose, itchy eyes, and coughing — though prevention measures differ.

In general, it’s important to keep your living space clean, keep your relative humidity at a reasonable place, and use HEPA filters to catch allergen particles. You can treat indoor allergens through a number of methods, including antihistamines, immunotherapy, and home remedies.

Need some extra support? Your online allergist is in. See how Cleared can finally make it easier for you to live comfortably inside your own home.


Allergies - Symptoms and causes | The Mayo Clinic

Dust Mite Allergy | AAFA

What is a HEPA filter? | US EPA

Mold Allergy - Symptoms, Prevention and Treatment | AAFA

Cockroach Allergy | AAFA.

Allergy skin tests | The Mayo Clinic


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