From the quick sting of a paper cut to living with arthritis every day, pain is a part of everyone’s life. And in fact, roughly 25% of people in the U.S. live with chronic pain. How does your body know when to feel this sensation?

Let’s take the paper cut as an example. When you experience this type of injury, specialized nerve cells detect the damage and send an alert to your brain to tell it your body is in danger. The brain then processes these signals and determines how to respond. Usually, this results in an instantaneous sensory signal that causes you to feel pain. While this may feel simple in the moment, it is the result of a complex interaction between the nervous system and the brain. When you’re in more serious danger, pain signals may also prompt you to move away from the source of injury (such as a hot stove) while also triggering the immune system to start responding to the damage.

When the body continues to signal the pain alarm even after an injury or illness has healed, short-term pain can become chronic. Chronic pain extends beyond an acute injury or accident, and can be caused by many factors, including arthritis, migraines or cancer. These conditions cause the nervous system to get stuck in a cycle of pain, making the body more and more sensitive to pain signals. Chronic pain is the most common disability in the U.S., and can contribute to anxiety, depression and disruptions to sleep.

No two people feel pain the same way. What might feel like a severe sharp sensation to one person can feel like dull ache to another. Age, sex and ethnicity may also influence how people feel pain.

Because everyone is different, there is no “one-size-fits-all” approach to treat pain. Specialized pain management clinics often use a blend of medications, talk therapy and lifestyle changes (such as exercise) to manage long-term symptoms. The next time someone says “ouch,” remember that pain is much more than just a moment of discomfort. It is a complicated conversation between your nervous system and your brain that can turn from acute to chronic over time.