ME/CFS – Causes, Symptoms and Comorbidities

ME/CFS is a complex illness where extreme fatigue and other symptoms reduce people’s ability to function. The illness can be triggered by physical or mental effort and doesn’t improve with rest or sleep. It affects a quarter of a million people in the UK and over one million in the US. It can be difficult to diagnose and many people are misdiagnosed.

There is no single diagnostic test for ME/CFS and a diagnosis can take months or years. However, the NICE clinical guideline for ME/CFS outlines what patients can expect from their health professionals in terms of symptom recognition, diagnosis and management. The ME Association fully supports the NICE clinical guideline and is working with NHS colleagues to ensure its implementation and an improvement in care for everyone affected by ME/CFS.

The name ME/CFS has changed over time. It was first called epidemic neuromyasthenia, then chronic fatigue immune dysfunction syndrome, atypical poliomyelitis, low natural killer cell disease and systemic exercise intolerance disease.

Experts still don’t know what causes ME/CFS, but it is thought to be a combination of biological and environmental factors. Some of the most commonly reported triggers include infections (such as viral, bacterial and herpesviruses), surgery, major hormonal changes (such as pregnancy and menopause), stress and poor diet. ME/CFS can also develop suddenly, often after an event or as a result of some sort of trauma.

Symptoms of ME/CFS can range from mild to severe and are typically worse after activity. They include post-exertional malaise, or PEM – a sudden, widespread muscle weakness, pain, unrefreshing sleep, trouble thinking clearly and memory problems, headaches, dizziness or lightheadedness, bloating and constipation and difficulties regulating temperature.

In some people, ME/CFS can be accompanied by other illnesses, called comorbidities. These can include fibromyalgia (widespread pain in the muscles), POTS (postural orthostatic tachycardia, an increase in heart rate when standing up) and gastroparesis or irritable bowel syndrome (bloating and constipation). Depression, anxiety and mast cell disorders are also common in ME/CFS.

ME/CFS can have a devastating effect on people’s quality of life and has been linked to depression, anxiety and isolation. It can lead to loss of employment, financial strain and a reduction in social interaction and can have profound impacts on family, friends and community. There is no known cure, but a number of approaches can help relieve symptoms. These include pacing, which involves matching level of activity to available energy; using sleep aids; avoiding triggers; and using medication for pain. More information about these approaches and support is available in our “Patient Resources” section. We need more funding to support research into a cure and better treatments. Please consider donating.