Are you one of those people who can't leave the house without a small bottle of hand sanitizer? Or do you go running for the closest hand sanitizer dispenser after shaking someone's hand? If you're constantly reaching for hand sanitizer, you may want to cut back. In the case of hand sanitizer, it's possible to use too much of a good thing.

"Keeping your hands clean is key when it comes to preventing the spread of germs and viruses that cause colds, flus and the dreaded norovirus," said Jeanne Gricoski, DO, internal medicine physician at Geisinger Orwigsburg. "But if you're using hand sanitizer too frequently, you may be keeping your hands too clean."

That's because, while it may seem like a no-brainer to fight getting sick by carrying pocket-size hand sanitizer, it can actually be harmful to your immune system in the long run.

"Alcohol-based hand sanitizers are very effective at keeping microorganisms at bay and preventing bacteria from getting into your system that can make you sick," Dr. Gricoski explained. "However, over sanitizing your hands can strip them of all germs."

Your immune system actually uses germs to build its own strength - your body needs to be introduced to germs in order for your immune system to know how to defend itself from invaders.

"Using hand sanitizer too often kills all microorganisms, including the harmless ones that help your immune system," Dr. Gricoski said.

Although you may be sanitizing your hands with the best of intentions in mind, over-sanitizing your hands can actually increase your risk of getting sick by not allowing your body to be exposed to bacteria and germs.

So what should you do?

"First and foremost, hand sanitizer should be used as a backup tool to hand washing," Dr. Gricoski said. "You should be washing your hands regularly and only using hand sanitizer when soap and water aren't available."

In other words, hand sanitizers shouldn't replace hand washing, but rather as a supplement to washing your hands.

Secondly, try to revert to common sense when it comes to keeping your hands clean.

"You should always wash your hands before and after preparing food or treating wounds, before putting in or taking out contact lenses, after using a bathroom or changing a diaper, after blowing your nose, and after handling garbage," Dr. Gricoski said.

And, of course, wash your hands if they look dirty.

If you're out and about and don't have access to soap and water, that's when you pick up hand sanitizer, but sparingly. You don't need to squirt sanitizer on your hands in between every aisle in the grocery store, but if you're about to try a food sample at the store, that's the time to clean your hands.