What is the new term for medically unexplained symptoms?

September 23, 2025 •

2 min read

An estimated 15% to 30% of all primary care consultations involve physical symptoms that lack a clear medical explanation. For years, these cases were referred to as “medically unexplained symptoms” (MUS), but evolving diagnostic criteria and patient feedback have led to a significant change in terminology. This shift reflects a more comprehensive, patient-centered understanding of these complex health conditions.

Quick Summary

The new umbrella term for conditions previously labeled as medically unexplained symptoms is Somatic Symptom and Related Disorders in the DSM-5, while broader terms like Persistent Physical Symptoms and Functional Somatic Disorders are also used to describe these conditions in clinical and research settings. The change in terminology emphasizes the realness of the symptoms and the distress caused, rather than focusing solely on the absence of a medical explanation.

Key Points

Somatic Symptom and Related Disorders: In the DSM-5, this new classification replaces older terms like "medically unexplained symptoms" (MUS) and "somatoform disorders" to describe persistent, distressing physical symptoms and the thoughts and behaviors associated with them.
Emphasizes Positive Diagnosis: The new terminology focuses on the presence of symptoms and the patient's excessive distress and impairment, rather than defining the condition by the absence of a medical explanation.
Avoids Patient Stigma: The older term MUS was often criticized for implying that symptoms were "all in the head," which invalidated the patient's experience and created stigma. The new terms aim for a more compassionate approach.
Adopts a Biopsychosocial Model: The modern understanding recognizes that complex interactions between biological, psychological, and social factors can cause real and distressing physical symptoms.
Alternative and Related Terms: Other phrases, such as Persistent Physical Symptoms (PPS), Functional Somatic Disorders (FSD), and Psychophysiologic Disorders (PPD), are also used in clinical and research settings for their neutral and patient-centric focus.
Treatment Focuses on Management: The goal of modern treatment is to help control symptoms and restore function through regular appointments, education, and therapies like cognitive-behavioral therapy (CBT), rather than exhaustive testing.

What led to the change in terminology?

For decades, the phrase "medically unexplained symptoms" (MUS) was widely used, but criticized because it often implied symptoms were "all in the head" and invalidated patients' distress. It also lacked a clear treatment path. New terminology aims to be more patient-centered and focuses on identifying a condition rather than excluding others.

The official new terms: Somatic Symptom and Related Disorders

The DSM-5 introduced "Somatic Symptom and Related Disorders" (SSRDs), replacing older terms like "Somatoform Disorders".

Key disorders within this category:

Somatic Symptom Disorder (SSD): Characterized by distressing physical symptoms and excessive thoughts, feelings, or behaviors related to these symptoms.
Illness Anxiety Disorder: Involves preoccupation with having or developing a serious illness, with minimal or no physical symptoms.
Functional Neurological Symptom Disorder (Conversion Disorder): Features nervous system symptoms not consistent with neurological disease but causing distress.

Other modern terminology for related syndromes

Alternative terms are used to provide less pathologizing labels:

Prominent alternative terms:

Persistent Physical Symptoms (PPS): Highlights the long-lasting nature and physical reality of symptoms.
Functional Somatic Disorders (FSD): An umbrella term for conditions with persistent physical symptoms stemming from disturbed bodily function.
Psychophysiologic Disorders (PPD): Emphasizes physical symptoms influenced by psychological factors.

How are the new terms different?

The new terminology adopts a biopsychosocial approach, recognizing the interplay of biological, psychological, and social factors in causing real symptoms, moving away from a rigid mind-body split.

Old vs. New Terminology: A Comparison


Aspect	Older Terminology (MUS)	Newer Terminology (SSRD, PPS, FSD)
Focus	Exclusionary diagnosis: Focuses on the absence of a medical explanation.	Inclusionary diagnosis: Focuses on the presence of real, distressing symptoms and the patient's response.
Patient Experience	Often invalidating; can imply symptoms are "all in your head."	Validating; confirms symptoms are real and distressing, regardless of origin.
Mind-Body Duality	Reinforces the separation of mind and body.	Embraces the mind-body connection; understands psychological stress can manifest physically.
Treatment Approach	Can lead to a cycle of unnecessary medical tests.	Focuses on managing symptoms, restoring function, and addressing related psychological factors.
Acceptability	Frustrating and stigmatizing for many patients.	More neutral and patient-centered, promoting better therapeutic alliances.

Implications for patients and physicians

The shift encourages physicians towards a holistic approach and validates patients' experiences. Effective management often involves a multidisciplinary team and therapies like cognitive-behavioral therapy (CBT).

The path forward

Moving away from MUS signifies progress in understanding and care. A biopsychosocial approach and new terminology help reduce stigma and improve treatment.

For more comprehensive information, an authoritative resource is available from the American Psychiatric Association.

Frequently Asked Questions

In the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5), the new category is called Somatic Symptom and Related Disorders. Within this, a common diagnosis is Somatic Symptom Disorder (SSD). Other terms include Persistent Physical Symptoms (PPS) and Functional Somatic Disorders (FSD).

No. The physical symptoms are very real and cause genuine distress. The older term was misleading and invalidating, which is why the terminology has changed. Modern understanding acknowledges a complex mind-body connection, where psychological factors like stress can influence physical sensations and manifest in real, measurable ways.

The change was driven by patient feedback and a better understanding of these conditions. The old term was stigmatizing and implied a diagnostic dead end, often leading to unnecessary testing. New terms are more patient-centered, focusing on the management of real, distressing symptoms and the behaviors around them.

No. While there is a related condition, Illness Anxiety Disorder (formerly hypochondriasis), SSD is different. SSD focuses on the patient's excessive thoughts, feelings, and behaviors in response to actual physical symptoms, which may or may not have a medical explanation. Illness Anxiety Disorder is a preoccupation with the fear of having a serious illness, with minimal or no symptoms present.

Functional Somatic Disorder (FSD) is a broad, umbrella term for conditions like fibromyalgia and irritable bowel syndrome, where the etiology is unknown. Somatic Symptom Disorder (SSD) is a specific diagnostic category from the DSM-5, defined by a patient's excessive emotional and behavioral response to their physical symptoms.

Symptoms can vary widely and affect multiple body systems. Common symptoms include chronic pain, fatigue, headaches, gastrointestinal problems (like IBS), and neurological symptoms (like weakness or dizziness).

Diagnosis is based on a thorough clinical evaluation of the patient's symptoms and their impact on daily life. Treatment often involves a multidisciplinary approach, including education, stress management, psychotherapy (such as Cognitive Behavioral Therapy), and regular check-ins with a healthcare provider to manage symptoms and improve function.