Fatigue is one of the most common symptoms we see in clinical practice. But there’s a big difference between feeling tired after a long week and experiencing the persistent exhaustion associated with Chronic Fatigue Syndrome (CFS).
People with chronic fatigue syndrome often describe it as feeling like their body’s energy system is broken. Even after sleeping, resting, or taking time off, they still feel depleted.
Let’s walk through what’s really going on.
What Is Chronic Fatigue Syndrome?
Chronic Fatigue Syndrome (also called Myalgic Encephalomyelitis or ME/CFS) is a condition characterized by long-term, severe fatigue that doesn’t improve with rest.
Common symptoms include:
• Persistent fatigue lasting 6 months or more
• Brain fog and difficulty concentrating
• Unrefreshing sleep
• Post-exertional malaise (feeling worse after activity)
• Muscle or joint pain
• Sensitivity to light, sound, or stress
One of the defining features is post-exertional malaise. Even mild activity can cause a crash that lasts for days.
Why Fatigue Happens in the First Place
Fatigue is rarely just about sleep.
In functional medicine, we often look at fatigue as a signal that one or more energy systems in the body are struggling, including:
• Mitochondrial energy production
• Hormone regulation
• Immune system activity
• Gut health and nutrient absorption
• Nervous system balance
When several of these systems are out of balance at the same time, the body shifts into a low-energy survival mode.
Common Root Causes We Look For
There is rarely one single cause of chronic fatigue syndrome. Instead, it often develops after multiple stressors build up over time.
Some of the most common drivers include:
Chronic infections
Viruses like Epstein–Barr, Lyme, or other persistent infections can keep the immune system activated.
Gut dysfunction
Inflammation in the gut can impair nutrient absorption and increase systemic inflammation.
Hormonal imbalances
Adrenal stress, thyroid dysfunction, and blood sugar instability can all contribute to fatigue.
Nervous system overload
When the body stays stuck in a stress response, energy production often declines.
Nutrient deficiencies
Low levels of B vitamins, magnesium, iron, or other nutrients can impair energy metabolism.
Why Many Patients Feel Dismissed
Many people with chronic fatigue syndrome are told that their labs are “normal” or that their symptoms are stress related.
While stress absolutely affects health, fatigue often has physiological causes that require deeper investigation.
Standard testing doesn’t always evaluate things like:
• mitochondrial function
• chronic immune activation
• subtle hormone dysregulation
• gut microbiome imbalance
When those pieces are overlooked, people can struggle for years without answers. We use applied kinesiology and various lab tests when warranted to assess these things with every patient.
A Root-Cause Approach to Recovery
Instead of trying to “push through” fatigue, recovery typically involves helping the body regain its ability to produce energy again.
This often includes:
• addressing underlying infections
• improving gut health
• stabilizing blood sugar
• supporting mitochondrial function
• balancing hormones
• regulating the nervous system
Healing usually happens step by step, not overnight.
But once the underlying drivers are addressed, many people begin to see meaningful improvements in energy, clarity, and resilience.
To find other docs that practice how I do, click here. For more health articles, click here. If you aren’t too short on time, tune into my podcast below to listen more about fatigue.