PTSD symptoms usually begin within three months of the traumatic incident, but sometimes they begin years afterward.
PTSD is diagnosed through a series of steps that include clinical tests and professional screenings.
Several at-home tests can also help you assess your symptoms.

Verywell / Ellen Lindner
Symptoms of PTSD in children and teens may not be the same as in adults.
Tests for Diagnosing PTSD
A number of assessment tools are used to diagnose PTSD.
The goal of CAPS-5 is to establish whether a person can be diagnosed with PTSD.
Additionally, this assessment is used to analyze symptoms the patient has experienced over the previous week.
Symptoms from the past two weeks are identified and assessed as they relate to the DSM-5 diagnosis criteria.
However, its important to remember that only a licensed mental health professional can make adiagnosis of PTSD.
In addition to supporting self-assessment with PTSD, it can also be used after a diagnosis to monitor symptoms.
Thus, it acts as a tool for diagnosis and assessing symptoms to understand improvement.
The test uses a five-point scale, asking patients to rank their symptoms from 0 to 4.
Treatment for PTSDis available and may include psychotherapy, medication, or a mix of the two.
Novel treatments for PTSD, such aspsychedelic therapy, are under investigation.
Several at-home self-screening tools can tell you whether you should see a healthcare provider for further assessment.
Healthcare professionals have additional tools for diagnosis.
American Psychiatric Association.What is posttraumatic stress disorder?
National Institute on Mental Health.Post-traumatic stress disorder.
2020 Mar;285:112779. doi:10.1016/j.psychres.2020.112779