The more sensitive to odor is actually the more sensitive sense of smell. The sense of smell is related to the mucous membrane of the olfactory area and the olfactory cells. The olfactory cells are olfactory receptors, which have more thick and dense villi on their surface, thus increasing the surface area of the cells and increasing the contact area with odor substances, which reach the olfactory mucosa with the inhaled air, causing the olfactory cells to become excited. The odorant substance reaches the olfactory mucosa with the inhaled air, which excites the olfactory cells. The more olfactory cells a person has, the more sensitive he or she is to smell, but everyone’s sense of smell is different, even the same person in different environments and physical states. If you have an overly sensitive sense of smell, or even smell an odor that causes nausea or vomiting, you need to check whether there is an allergic disease and whether there is a decrease in your immune system. Avoiding exposure to overly irritating gases and dusts can help protect the health of the respiratory tract.