A condition that develops in some people who are diagnosed with cancer. Symptoms of cancer-related post-traumatic stress (PTS) include having frightening thoughts or trouble sleeping, being distracted or overexcited, feeling alone, or losing interest in daily activities. Symptoms may also include feelings of shock, fear, helplessness, or horror. Cancer-related PTS can occur anytime after diagnosis, including during or after treatment. Relaxation training, counseling, support groups, and certain medicines may be used to reduce symptoms of PTS.