Your brain quickly adapts to new smells. What smells pungently strong on the first sniff becomes almost undetectable a few minutes later. This phenomenon, called odor fatigue, is similar to the way the hum of an air conditioner fades into background noise, but odor fatigue is more powerful. That’s because once you lose track of a smell, you can’t will yourself to get it back—at least not without first leaving the room and smelling something else.
Odor fatigue makes perfect sense when you consider the evolutionary role of smell. Your body is more interested in using smell to detect things than it is in keeping track of them. Once you notice a smell and decide how you want to react, it’s time to move on so you can detect the next potentially important odor.
Now that you understand how odor fatigue lets you ignore prolonged smells, there are a few practical bits of advice to consider:
• To determine if an object or room in your house smells, start by walking out the door and giving your nose a break. Then step back inside and pay attention.
• To determine if you have body-odor issues, you’ll need the help of a friend who can sniff you out.
• Just because you can ignore a smell doesn’t mean you should. Irritants and even toxins, ranging from cleaning products to cigarette smoke, are easy to ignore if you live with them, but they might not be so easy on your lungs. If in doubt, open a window and get some fresh air.
Source of Information : Oreilly - Your Body Missing Manual