Illness anxiety disorder is a mental condition where the patient worries excessively about becoming seriously ill, despite the fact that their symptoms do not warrant such a conclusion. This disorder is also known as hypochondria. However, the diagnostic manual published by the American Psychiatric Association no longer lists hypochondria as a diagnosis.Instead of hypochondria, people are now diagnosed with illness anxiety disorder. In illness anxiety disorder, the patient is concerned about uncomfortable or unusual physical feelings being a sign of some serious medical problem.
The main problem that people with illness anxiety disorder suffer from is the anxiety and stress itself. The distress reaches a point in which normal day to day functioning is compromised. This can be either because the distressing thoughts preoccupy the person or the person avoids normal life activities because of their fear of getting ill.Illness anxiety disorder is a long-term condition that can vary in severity. It can get worse with age or with life stress. However, psychological therapy and possibly medication can treat the disorder.There is a related disorder called somatic symptom disorder. In this disorder, the patient becomes preoccupied with the physical symptom itself. They might have pain or dizziness. However, the patient does not worry about the possibility that the symptoms underlying a more serious condition.The precise cause of illness anxiety disorder isn't well understood. However, the following factors might be involved:

- Beliefs - The person might have an issue with experiencing uncertainty over uncomfortable or unusual bodily feelings. This may result in you thinking that all body sensations are serious.
- Family - You might end up with the disorder if your parents had similar fears about their health or your health.
- Past experience - If you have had a serious illness as a child, then unusual sensations may frighten you into believing that they are more serious than they actually are.