You may stink and not even know it. 

That’s according to Dr. George Preti. He’s an organic chemist, and he says when we're exposed to a new odor, we smell it right away. But if we’re constantly around the bad smell, we don’t even notice it anymore. It’s called “smell-specific anosmia," or an inability to detect that smell. 

So here are a few things to beware of that could make you smell:  

  • First: Gum disease. When bacteria inflames your gums, it triggers gum disease and a byproduct is volatile sulfur compounds, which basically make your breath smell like rotten eggs. Brushing helps a little bit. But the only way to kill the odor is to schedule a deep dental cleaning to remove plaque buildup on your teeth.

  • Then you may smell because you went on a no carb diet. But without carbs, you’ll start to smell like sour fruit or nail polish. That’s because your body has gone into a fat-burning state called ketosis. So add back in carbs like spinach and broccoli. They’re packed with chlorophyll, which is what makes plants green. An Oregon State University study found that the chlorophyll acts as an internal body deodorant.  

  • Another reason why you may stink and not know it: Your prescription pills. Anti-depressants can open the floodgates of sweating. And the more you sweat, the more odor-causing bacteria multiplies. Also a common side effect of allergy and high blood pressure meds is dry mouth. And that’s a recipe for bad breath, since we need saliva to help flush out our mouth and keep it clean. But don’t quit your meds. Talk to your doctor about how to combat the problem. 

  • One last reason you stink? You’re lactose intolerant. That means you’re deficient in the enzyme that digests dairy products, and it can leave a person gassy after they consume dairy. A large majority of the world's population is lactose intolerant, especially people of Asian descent and people with darker skin. To combat it: Go for plant-based alternatives like soy or almond milk, soy yogurt and cheese made from nuts like cashews or soy.