5 Causes Of Hard-To-Beat Post Cancer Fatigue



Cancer survivors struggling with fatigue know that it's REAL.  But what causes persistent cancer related fatigue?  There are multiple, overlapping sources that fall into two categories in my mind: conventionally "treatable" and "not so easy for your doctor to fix."

Medical Causes

Post treatment fatigue should be thoroughly evaluated by your cancer treatment team for conventionally treatable disorders.  The medical causes might include anemia (low red blood cells), infection, dehydration, electrolyte imbalance (sodium, potassium, magnesium and others), severe protein calorie malnutrition requiring medical feeding, organ dysfunction, pain, hormone imbalance, medication side effects, or mental illness.  These are issues we need medical science and a skilled cancer team to help us solve.

Stubborn Causes of Post Cancer Treatment Fatigue

Then there are the more insidious and stubborn causes, that are "not so easy for your doctor to fix":

1. Deconditioning

Deconditioning is a term for being really out of shape to the point of physical deterioration.  Essentially, inactivity and the biologic effects of cancer treatment cause your muscles to get smaller and your body to function less efficiently.  People receiving treatment for cancer are often so tired that they don't move their bodies.  This results in even more fatigue.  It's a viscous cycle and once caught, cancer survivors wind up deconditioned to the point they cannot tolerate average daily physical activity.  They can feel short of breath when they move and feel absolutely exhausted doing things that were once easy for them.

2. Poor Appetite

Most cancer treatment - chemo, surgery, and radiation - can diminish appetite.  Chemo and immunotherapy make things taste differently and upset your stomach.  Radiation can also upset your stomach and inflame your intestinal tract.  Surgery and anesthesia can cause a slow moving gut or even change the structure of your gut depending on the procedure required to treat your cancer.  And frankly, sometimes people undergoing treatment are just too tired to eat.  Decreased appetite results in less nutritional intake which can leave a body weakened and fatigued.

3. Stress and Fear

Being diagnosed with cancer, undergoing treatment and coming out the other side is a life altering experience.  For many cancer survivors, the experience catapults them to a place they'd never imagined before, where the consciousness of mortality rocks their core and changes who they are as a person.  Nobody can adjust to this new place quickly.  Cancer survivors struggle with stress and fear, living in a pressured state that can lead to hormonal changes and cause sleeping problems and mental exhaustion.  

4. Inflammation

Cancer treatment causes a state of generalized inflammation in your body.  Inflammation is an immune system adaptation that normally protects us from harmful infections and injury.  But when inflammation occurs in response to cancer treatment, the normal inflammatory signals in your body go haywire.  The inflammatory response plays a maladaptive game of telephone with your nerves and hormones which augments the dysfunctional response.  The result is exhaustion and cognitive dysfunction, often lasting months after your cancer treatment has ended.

5. Brain Fog

Chemotherapy, radiation, and hormonal therapy can cause changes in a cancer survivor's ability to think.  Your mental pace feels slow and your memory may be altered.  For some this is embarrassing and distressing.  This effect can be permanent and leaves survivors unable to do tasks as efficiently as they once did.  The strain of the cognitive effort, frustration with your abilities, and the reality that you are not as mentally capable as before treatment can lead to fatigue.


The above causes of cancer related fatigue are difficult to treat.  There’s no quick pill to fix it.  Rest doesn't work and can even exacerbate fatigue.  The GOOD NEWS is - there's a treatment for fatigue that you can administer starting right now.  A restorative diet, exercise, and mindfulness practices are proven to help improve fatigue in cancer survivors.

If you aren’t sure where to start, why not try Brio's FREE Morning Checklist?  The checklist is a seven point solution to cancer survivor fatigue, leveraging movement, mindfulness, and nourishment to fight fatigue and feel better in the process.  Click the button below to download it for free.

Visit Brio often for great tips about how to fight fatigue and live with vitality, clarity, calm, and overall good health after cancer. Take care, Cancer Survivors!