Education
Understand Cachexia
Cachexia affects up to 80% of people with advanced cancer — yet most patients have never heard the word. Here is what you need to know.
What Is Cachexia?
Cancer cachexia is the unintentional loss of body weight that often occurs in people living with cancer and is due to the tumor and immune cells releasing factors that break down muscles and fat, and act on the brain to decrease appetite. An unintentional weight loss threshold of 5% or more over six months is used to diagnose cachexia, but in people with a low BMI or with low muscle mass already, an unintentional weight loss of 2% or more may be used. Cachexia affects 50% of all people with cancer, up to 80% of people living with advanced cancer, and may contribute to approximately 30% of cancer-related deaths.
Cancer cachexia is a complex inflammatory and metabolic syndrome. The cancer causes a fundamental change in whole body metabolism, driven by the interaction between the tumor and the immune system, which triggers widespread inflammation and metabolic disruption that cannot be fully reversed by eating more.
Importantly, cachexia is not your fault. It is not a failure of willpower or appetite. It is a disease process driven by your cancer.
Symptoms & Warning Signs
Cachexia presents differently in different people, but common signs include:
- Unintentional weight loss
- Loss of muscle mass, even when weight appears stable
- Persistent fatigue that does not improve with rest
- Loss of appetite
- Weakness and reduced physical function
- Difficulty tolerating cancer treatments
- Changes in metabolism — feeling cold, burning calories faster than usual
Cachexia is often underdiagnosed, especially in patients who are overweight or obese, because weight loss may not be immediately obvious even as muscle is being lost.
Stages of Cachexia
Cachexia typically progresses through three stages:
Understanding which stage you or your loved one is in matters — it shapes which interventions may be helpful.
Treatment & Management
Currently, there are no FDA or EMA-approved pharmacological treatments specifically for cancer cachexia — though there is hope that this will change in the near future, with multiple clinical trials underway, including late-stage trials.
Management today is multimodal, meaning it combines several approaches:
Talking to Your Care Team
Many oncology teams do not routinely screen for or discuss cachexia. You may need to bring it up yourself. Consider asking:
- “I’ve been losing weight or losing muscle — could this be cachexia?”
- “Should I see a dietitian or nutritionist?”
- “Are there any clinical trials for cachexia that I might qualify for?”
- “What can we do now to preserve my strength and function?”
You have the right to ask these questions. Cachexia is a real clinical condition and deserves the same attention as your cancer treatment.
We have created a printable handout to help guide this conversation: Download the “Talking to Your Care Team” handout (PDF). Bring it with you to your next appointment.
Have more questions?
Our community has patients and caregivers who understand what you are going through. You don’t have to figure this out alone.