The possible causes of a heightened sense of smell, for both men and women, may be stress, epilepsy and migraines, and in women only, hormonal changes during certain times of the menstrual cycle and pregnancy. The trait may be hereditary and genetic, or it can be exacerbated by environmental factors such as medication. The scientific name for a heightened sense of smell is hyperosmia. The cells that receive scents are called olfactory sensory neurons, and they are found in the upper parts of the inside of the nose. These cells send messages to the brain, which identifies the odor. Research is ongoing on the condition of hyperosmia, but these are some of the common causes.