"People don't understand the emotion tied to flashbacks. It’s like it’s happening all over again, and you're having the same physiological reactions." - Hurricane Katrina survivor Marvin Turner

Symptoms of post-traumatic stress disorder (PTSD) can be terrifying. They may disrupt your life and make it hard to continue with your daily activities. It may be hard just to get through the day.

PTSD symptoms usually start soon after the traumatic event, but they may not happen until months or years later. They also may come and go over many years. If the symptoms last longer than 4 weeks, cause you great distress, or interfere with your work or home life, you probably have PTSD.

Even if you always have some symptoms, counseling can help you cope. Your symptoms don't have to interfere with your everyday activities, work, and relationships.

Most people who go through a traumatic event have some symptoms at the beginning but don't develop PTSD.

There are four types of symptoms:

Reliving the event

Bad memories of the traumatic event can come back at any time. You may feel the same fear and horror you did when the event took place. You may feel like you're going through the event again. This is called a flashback. Sometimes there is a trigger: a sound or sight that causes you to relive the event. Triggers might include:

• Hearing a car backfire, which can bring back memories of gunfire and war for a combat veteran.
• Seeing a car accident, which can remind a crash survivor of his or her own accident.
• Seeing a news report of a sexual assault, which may bring back memories of assault for a woman who was raped.

Avoiding situations that remind you of the event

You may try to avoid situations or people that trigger memories of the traumatic event. You may even avoid talking or thinking about the event.

• A person who was in an earthquake may avoid watching television shows or movies in which there are earthquakes.
• A person who was robbed at gunpoint while ordering at a hamburger drive-in may avoid fast-food restaurants.
• Some people may keep very busy or avoid seeking help. This keeps them from having to think or talk about the event.

Feeling numb

You may find it hard to express your feelings. This is another way to avoid memories.

• You may not have positive or loving feelings toward other people and may stay away from relationships.
• You may not be interested in activities you used to enjoy.
• You may forget about parts of the traumatic event or not be able to talk about them.

Feeling keyed up

You always may be alert and on the lookout for danger. This is known as increased emotional arousal. It can cause you to:

• Suddenly become angry or irritable.
• Have a hard time sleeping.
• Have trouble concentrating.
• Fear for your safety and always feel on guard.
• Be very startled when someone surprises you.

Other symptoms