During a trauma, your body responds to a threat by going into “flight or fight” mode. It releases stress hormones, like adrenaline, to give you a burst of energy. Your heart beats faster. Your brain also puts some of its normal tasks, such as filing short-term memories, on pause.

PTSD causes your brain to get stuck in danger mode. Even after you’re no longer in danger, it stays on high alert. Your body continues to send out stress signals, which lead to PTSD symptoms. Studies show that the part of the brain that handles fear and emotion (the amygdala) is more active in people with PTSD.

Over time, PTSD changes your brain. The area that controls your memory (the hippocampus) becomes smaller. That’s one reason experts recommend that you seek treatment early.

What Are the Effects of PTSD?

There are many. They may include disturbing flashbacks, trouble sleeping, emotional numbness, angry outbursts, and feelings of guilt. You might also avoid things that remind you of the event, and lose interest in things that you enjoy.

Symptoms usually start within 3 months of a trauma. But they might not show up until years afterward. They last for at least a month. Without treatment, you can have PTSD for years or even the rest of your life. You can feel better or worse over time. For example, a news report about an assault on television may trigger overwhelming memories of your own assault.

PTSD interferes with your life. It makes it harder for you to trust, communicate, and solve problems. This can lead to problems in your relationships with friends, family, and coworkers. It also affects your physical health. In fact, studies show that it raises your risk of heart disease and digestive disorders.

PTSD can happen to anyone at any age, including children. In fact, about 8% of Americans will develop the condition at some point in their lives.

Women have double the risk of PTSD. That’s because they’re more likely to experience a sexual assault. They also blame themselves for a traumatic event more than men do.

About 50% of women and 60% of men will experience emotional trauma sometime in the lives. But not everyone develops PTSD. The following factors increase your risk: