• Unwanted Memories
Though not often considered an "intrusive thought" in the medical sense, many people experience persistent, unwanted memories. Those with PTSD are especially prone to these types of memories, but anyone may have a memory that causes them significant distress, and those with anxiety are more likely to have that memory pop up at unwanted times.
• Violent Thoughts
Thoughts of violence and aggression may also be common in those with some types of anxiety, especially obsessive compulsive disorder. Generally, these are thoughts where the person imagines themselves doing violent/aggressive things. However, one could consider worries about danger happening to other people to be violent thoughts as well.
• Sexual Thoughts
Like violent thoughts, a person can have unwanted sexual thoughts. Sometimes these sexual thoughts are paired with religious-induced shame, while other times the sexual thoughts may also be somewhat violent in nature. These are also more common with those with specific types of anxiety disorders.
People who experience anxiety and panic attacks frequently describe having to deal with the negative side-effects of troubling or intrusive thoughts that creep into their minds. These thoughts can range from worries about health, concern over loved ones or fear that a loved one may ‘die’, some describe suicidal thoughts or even fears that do not make any rational sense at all but continue to linger in the mind.
Sometimes, the unwanted, troubling or intrusive thoughts come from previous experiences, such as flash backs or fear something may happen again. Other times they are simply bizarre, leaving the person worried as to why such strange thoughts are occurring. In all these cases, the person is upset by the anxious thoughts because they are causing distress and worry.