Warning: This article might freak you out a little. After you read this, you will probably want to wash your hands (see #7 below for the proper way to do so). At the risk of causing a nationwide outbreak of spring cleaning in the middle of winter, Healthline picked the brains of a couple of experts to get the dirt on the dirtiest places in your home. What we found was a mix of duh (kitchen sink) and wow (just-washed laundry). The goal is to remind you (and ourselves) of what you already know:

  • Germs are everywhere.  Bacteria, viruses, fungi, and protozoa are in your home right now. In optimal conditions, bacteria can divide every 20 minutes; that means (do the math) one single bacterium cell can multiply to 70 trillion in a single day.
  • Germs can make you sick.  The good news is that your immune system is effective at guarding against most microorganisms. The bad news is, 70 trillion is a big number and some germs, especially viruses, are really good at mutating into things your body doesn't recognize.
  • It doesn't take much effort to keep things clean and healthy.  Soap and water. Bleach and water. Disinfecting wipes. Common sense. With these simple weapons, the battle against germs can be won.

What we also learned is that, when it comes to germs, people often resort to an "out of sight, out of mind" philosophy. "Even the most careful people will let their guard down," says Barbara Citarella, a certified infection preventionist and president of the healthcare consulting firm RBC Limited. "As vigilant as we might be, we are going to neglect certain areas from time to time." Barb, who has long list of abbreviated certifications that often follow her name, is a member of the Association of Practitioners in Infection Control (APIC), an organization that strives to keep Americans healthy and convince them to do one important thing—wash their hands.

Barb and other experts helped us put together the following list of problem areas, complete with tips on how to keep them clean. Read on, and grab a disinfecting wipe—you'll probably want to start wiping down your computer keyboard before you finish.

1. The Kitchen

The sink. Dish towels. Sponges. Counters. The floor. Refrigerator. Germs tend to gather in high-traffic areas, and they love moisture. Well, there is no other place in the home that is more wild and wet than the kitchen (we'll get to the bathroom later). Dish towels and sponges are especially problematic, because they hold moisture and we tend to use them for multiple tasks—drying our hands, wiping up coffee spills and raw chicken juice, washing dirty dishes, and drying clean dishes. The kitchen sink is a no-brainer and gets a lot of attention, but the faucet hardware gets just as dirty after you handle raw food or dirty dishes and then turn the water on and off. Other areas include the refrigerator door handle and cabinet knobs.

Keep it clean:  Barb suggests switching out dish towels at the end of each day and running the sponges through the dishwasher. You can also soak the sponges in a bleach-water solution of 1 part bleach to 10 parts water or simply throw them away after several uses. When cleaning the sink, pay extra attention to the drain and the faucet hardware.

2. Knobs, Handles, and Switches

This one seems obvious, but how often do you walk around your home and wipe off doorknobs, cabinet handles, and light switches?

Keep them clean:  Once a week, walk around your home and wipe off doorknobs, cabinet handles, and light switches. It's that simple. Use disinfecting wipes, and don't use the same wipe for more than a few places before grabbing a fresh one.

3. Makeup Bag

Pay attention, ladies. Your makeup applicators are a lot like kitchen sponges. They have nooks, crannies, and bristles that are prime real estate for microorganisms. And the germs that live there can lead to skin and eye infections.

Keep it clean:  No, you don't have to throw away all your makeup right away. Most experts recommend replacing your powders and eye shadows every two years, foundation every year, and mascara every three months. "Women should also clean their makeup applicators about every two weeks," says Alesia J. Wagner, DO, medical director for U.S. HealthWorks Medical Group. "And when you do purge your old makeup, don't forget to wipe out the empty bag." Regular soap and water is fine for most applicators, but you can use alcohol on the brushes. And keep it to yourself. You don't share your toothbrush with others; you shouldn't share your makeup brush either.

4. Laundry

Yes, even clean laundry. If you're like most people, you wash the majority of your laundry in cold water. While it's better than wearing your jeans for an entire month before washing them, a cold water-detergent mix won't kill all the microorganisms on your clothes. And wet laundry left unattended in a machine, even for short amount of time, is like The Fertile Crescent for germs.

Keep it clean:  This is one of Barb's main areas of concern, and she had a lot of advice. First of all, tread lightly when carrying dirty laundry through the house. Throwing it around will spread germs from one room to the next. And don't shake out your clothes or sheets before putting them in the wash. After you do put it in the machine, wash your hands and wipe out the empty laundry basket before putting clean laundry back in. If possible, wash your clothes in hot water, especially your undergarments. And transfer the clothes to the dryer immediately after they are done washing. If they do sit for more than 30 minutes, run them through the cycle again.

For people who use laundry mats or shared laundry facilities, you should spray or wipe the washer drum with disinfecting solution. Just make sure you wait the recommended amount of time before adding your laundry. And be sure to wipe down any surfaces you use to fold clothes. 

5. Home Office/Cell Phone/Electronics

On average, an office desk has 400 times more bacteria than a toilet seat. It's not surprising; we spend a lot of time there, and it holds two of the safest havens for germs: the computer and telephone. Plus, the toilet is cleaned regularly for obvious reasons. Remote controls, computer keyboards, phones, stereos, and DVD players get touched way more than the toilet, are shared by multiple family members and guests, yet they are cleaned a lot less often.

Keep them clean:  Use common sense here, and wipe down keyboards, mice, phone buttons and receivers, stereo knobs, and cell phones often. Don't forget your actual desk too. You can find component-specific cleaning supplies at electronics stores. However, most disinfecting wipes are safe for electronics; just make sure to read the label before using them. And many companies make anti-microbial cell phone covers for a variety of brands and models.

6. Bathroom

The toilet, bathtub/shower, and sink are all obvious offenders. Thus, they are on most people's regular cleaning rotation. Barb also pointed the finger at plastic shower curtains; the crud that gathers on the bottom after extended use is bacteria (not soap scum).

Keep it clean:  "Bubble bath does not clean the tub," says Barb. (So much for multitasking.) There are plenty of reliable cleaning products on the market to use in the bathroom. Use an old toothbrush to clean around drains and faucets. Pay special attention to the floor area around the toilet and the little cup that holds your toothbrush.

7. You

Think about it. Bathtubs, computers, kitchen sinks, and doorknobs don't leave and return to your home multiple time each day. So how do these hoards of germs get into your home? You bring them in.

Keep yourself clean:  Wash your hands. "We see signs in restaurants that employees must wash their hands before preparing food," Dr. Wagner says. "Why would that be any different in our own homes?" It shouldn't be any different — in our homes, workplaces, or anywhere else we go. But oddly enough, many people don't wash their hands properly. "Friction is the key," says Barb. "Interlace the fingers and wash the tops of the hands and around the thumbs. Not just the palms." And duration is also important — approximately 20 to 30 seconds — or as Barb suggests, the amount of time it takes to sing a couple of rounds "Row Your Boat" or "Yankee Doodle Dandy." She also mentioned that singing is a great way to make it fun for kids, but we all could use more fun in our lives, right? Wash — and sing — to your heart's content.

Disclaimer:  Now that you are sufficiently freaked out, you should know that there is such a thing as "too clean." In other words, don't start hosing off guests when they walk through your door, and don't obsessively clean your kitchen all day, every day. "If we kill all the germs in our environment, then our bodies won't be able to build up any resistance," says Barb. "People shouldn't take it to the nth degree. We just encourage them to use common sense. When you do your regular cleaning—once a week for most people—just make sure you are thorough."