Losing someone we love is one of the hardest experiences in life. It can leave us feeling broken emotionally and spiritually, and healing takes time—often years.

Some people believe we can sense when life is nearing its end. Scientists have studied this idea and discovered that, when the body begins to change, it releases certain chemical compounds. One of these is called putrescine. While it is part of a natural process, research shows that humans subconsciously react to it.

Experiments by Arnaud Wisman (University of Kent) and Ilan Shira (Arkansas Tech University) found that people exposed to this compound often reacted by moving away from the source. This is similar to the instinctive “fight-or-flight” response seen in animals.

Interestingly, humans also react to other natural scents, such as sweat from fearful situations. These smells can trigger an automatic heightened awareness, making people more alert to their surroundings.

The study suggests that our sense of smell influences us more than we realize—shaping emotions, preferences, and even instincts for safety. Unlike pheromones, which attract, compounds like putrescine act as natural warning signals, often causing people to keep their distance without even knowing why.