Medically Unexplained Symptoms (MUS)
What are Medically Unexplained Symptoms?
Medically Unexplained Symptoms (MUS) are physical symptoms where medical tests are unable to identify a clear physical cause. The symptoms are real and distressing. They are not made up and are potentially treatable. MUS are common experiences and, in some cases, can become persistent and debilitating.
Although physical investigations are important in ruling out other diagnosis, sometimes MUS can be diagnoses based on a medical interview and examination.
Recent evidence suggests that there are subtle brain changes in patients with MUS.
What are common types of Medically Unexplained Symptoms?
There are different types of MUS disorders depending on the type of symptom experienced and the particular system involved. Some common examples are:
Dissociative seizures (also called non-epileptic attack disorder) – a condition in which people experience attacks resembling epilepsy but the brain electrical activity is not altered.
Irritable bowel syndrome – a condition where people have bowel symptoms including pain, bloating, constipation and diarrhoea but no physical cause can be found.
Chronic pain – a condition in which tissue damage has healed but the nerves continue to remain sensitive to pain.
Is there a better term to describe MUS?
The MUS term is not ideal because the word “unexplained” carries negative implications. A better term that may be used is “Functional Disorder” and this implies that there is no abnormality in the structure but a defect in the functioning.
What is Functional Neurological Disorder?
If the MUS is mainly in the form of neurological (nervous system related) symptoms, the term used to describe this condition is called “Functional Neurological Disorder” or FND in short. People suffering with FND can experience dissociative seizures, weakness, numbness, visual loss, speech difficulties and swallowing difficulties among other symptoms. The term FND is more preferable to MUS.
What causes MUS?
It may be difficult to attribute a direct cause and therefore it may be helpful to think of multiple factors that may come together to cause MUS. As tests are unable to identify a physical cause, these symptoms are thought to have a psychological origin. The mind is very powerful and there are strong links between the body and the mind. Psychological stress or traumatic experiences can sometimes be a trigger for the symptoms. Additionally, our previous experience of physical illness, family history and our mental model of how the body works are important considerations. However, in some people with MUS, there might not be any psychological factor identified.
Sometimes, patients with MUS can also have depression and anxiety and this can increase the level of distress. Depression can also lower pain threshold so the pain experience can get magnified.
Can MUS be treated?
The treatment of MUS starts from a good clinical assessment and a positive diagnosis. Understanding the diagnosis is quite important. Physical investigations are unlikely to help and may even increase risk of harm from the tests themselves. Looking up the symptoms online can raise anxiety levels. This can also become a barrier to recovery.
Treatment is usually in the form of psychological therapy initially aimed at exploring the symptoms and its impact. Addressing past trauma can help some patients. Treatment of depression and anxiety with medication can also be helpful to manage the symptoms in a better way.
Some patients may need to see a team of professionals including psychiatrists, psychologists, physiotherapists and occupational therapists. The treatment plan needs to be specific to each patient and a ‘one size fits all’ approach does not work.
Why do patients with MUS face stigma?
Unfortunately, the general awareness of MUS is still poor and patients can face stigma from health professional as well as from the general public. MUS can be confused with malingering (making up symptoms for an external gain such as financial gain) and this can attract negative attention.
MUS sits at the interface of physical and psychological health and patients may fall between conventional health care teams that are designed to treat either physical or psychological health disorders.