Understanding and Managing the Non-Pancreatitis Symptoms of Familial Chylomicronemia Syndrome
When people talk about familial chylomicronemia syndrome (FCS), they often focus on acute pancreatitis. This severe abdominal pain is a serious and frightening part of the disease. But for many people living with FCS, the disease is much more than just these attacks of abdominal pain.1
Many people with FCS feel unwell most of the time and live with a lot of chronic symptoms. These symptoms happen even when they are not having a pancreatitis attack.1
You may feel a deep, constant exhaustion. You may feel like your mind is cloudy—a feeling often called 'brain fog.' These symptoms are not 'just in your head.' They are a real, physical part of FCS. Continue reading to understand the possible causes and why it is vital to share all of your symptoms with your medical team.1
The daily burden beyond pancreatitis
Living with FCS means managing more than just the risk of pancreatitis. Studies show that people with FCS face many symptoms every day. These symptoms have a major impact on daily life. They can affect work, social activities, and emotional well-being.1
Research helps us understand this patient experience. A 2023 qualitative study interviewed people with FCS about their lives. The study confirmed that pancreatitis was the most impactful event. But patients also reported other major chronic problems. These problems included severe fatigue and impaired cognitive function, or "brain fog."1
Other symptoms may include:1,2
- Nausea and vomiting
- Fever
- Bloating
- Loss of appetite
These daily symptoms create a constant burden. This burden is separate from the sudden pain of an acute attack. It confirms that FCS affects the entire body.1
Understanding deep fatigue and brain fog
Two of the most difficult chronic symptoms of FCS are fatigue and brain fog.1
Physical fatigue
This is not the same as feeling tired after a long day. People with FCS often describe a deep, physical exhaustion. This fatigue can make normal daily tasks feel overwhelming. It is a weakness or lack of energy that does not go away, even with rest.1,2
Brain fog
"Brain fog" is the term many people use for cognitive symptoms. People report having serious difficulty thinking. They may struggle with:2
- Forgetfulness or memory loss
- Difficulty concentrating or focusing
- Feeling "cloudy" or "foggy"
- Taking longer to process thoughts
These symptoms are common in FCS patients. In fact, researchers developed a tool to measure the daily impact of FCS. This tool is called the FCS-Symptom and Impact Scale. It tracks 4 main symptoms. Two of those 4 symptoms are "physical fatigue" and "difficulty thinking." This shows how real and important these cognitive and physical symptoms are.2
Why do these symptoms happen?
Doctors are still learning the exact reason for this fatigue and brain fog. The main theory is linked directly to the high level of fats in the blood.1
FCS is a genetic disorder. It prevents the body from breaking down fats called chylomicrons. This causes extremely high levels of triglycerides in the bloodstream. When the blood is full of these thick fats, its consistency changes.3
The blood can become thick and "sludgy." This is sometimes called hyperviscosity. Experts believe this thick blood does not flow easily through small blood vessels. This may reduce the amount of oxygen and nutrients that get to the brain and muscles. This lack of good blood flow could directly cause feelings of fatigue and cognitive problems.3
Another hypothesis is inflammation. The constant presence of so many chylomicrons may trigger low-level inflammation throughout the whole body. This chronic inflammation is known to cause fatigue and make you feel generally unwell.3
The emotional and mental impact of FCS
Living with constant physical symptoms takes a toll on your mind. The daily burden of fatigue, brain fog, and abdominal pain is heavy. This can cause significant psychological stress and can impact quality of life. You may feel overwhelmed, anxious, sad, or isolated. It is just as important to discuss your emotional well-being with your doctor as the physical symptoms.1,4
Your symptoms are important: Talk to your medical team
You may be used to focusing only on abdominal pain when you talk to your doctor. You may think fatigue or brain fog is just stress. You may not think they are related to your FCS.
Your doctor needs the full picture to help you. Reporting your fatigue helps them understand your total disease burden. If you feel exhausted all the time, tell them. If you cannot concentrate at work, tell them.
This is especially important if you do not have a diagnosis yet. Many people live with these symptoms for years before finding out they have FCS. Reporting these "other" symptoms may help your doctor connect the dots.
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