How Is Chronic Fatigue Syndrome (CFS) Diagnosed?

How is Chronic Fatigue Syndrome diagnosed? Unfortunately the only way to diagnose CFS is to rule out all other possible causes of your fatigue.

Fatigue is one of the most poorly managed and confusing conditions in all of medicine. And part of the reason why is that no one has decided what fatigue really is.

For example, your doctor may have diagnosed you with:

chronic fatigue syndrome (CFS),
myalgic encephalomyelitis (ME),
systemic exertional intolerance disorder (SEID)

Even the names for your fatigue are confusing!

What is fatigue?

Although it is difficult to diagnose, there is a medical definition of fatigue. It is defined as the difficulty or inability to initiate activity.

According to the medical community, people who suffer from fatigue will:

Feel weak
Have a hard time being active for any length of time
Struggle with concentration, memory, and/or emotional stability

Someone suffering from fatigue may have one or more of these symptoms, or even have these symptoms while suffering from another health issue.

Diagnosing fatigue can also depend on how long it lasts. There are three types:

Acute fatigue
- Lasting one month or less
Subacute fatigue
- Lasting between one and six months
Chronic fatigue
- Lasting more than six months.

How is CFS diagnosed?

Before 2015, CFS was diagnosed by ruling out other health issues. Even now doctors will generally diagnose CFS only after your lab tests for other diseases/illnesses come back within the normal ranges. (6)

In 2015, the Institute of Medicine (IOM) redefined the the way CFS is diagnosed. At the same time, they re-named the disease. Today, CFS is known as systemic exertion intolerance disease (SEID). Not surprisingly, the name change has not caught on.

Along with changing the name, the Institute of Medicine also made it more difficult to be diagnosed.

The difference between CFS & SEID

The major differences between CFS and SEID are as follows:

There needs to be a specific point in time where your fatigue began. It cannot have happened your whole life.
Your fatigue cannot be associated with any exercise or fitness program.
Your fatigue cannot be alleviated with rest.
Unrefreshing sleep now needs to be associated with the fatigue.
You need to experience either a decline in your cognitive abilities or intolerance to standing upright.

These new questions force doctors to run more tests on their patients to rule out other possible causes of fatigue. This makes a diagnosis of CFS (or SEID as it’s now known) more difficult. It also encourages doctors to investigate all possible causes of fatigue before diagnosing CFS. I believe this to be a very important development in the treatment and management of the illness.

So with all of these changes in mind, you may be wondering if you’ve even been properly diagnosed. Let’s take a look at the criteria for a CFS diagnosis before 2015 and now.

First, I will ask you a series of questions based on the method of diagnosis from before 2015.

Take out a pen and paper to answer the questions in order. After you’ve finished answering the questions, the answers are just below the questions.

CFS diagnostic criteria (questions)

1. How long has your fatigue been present?

2. What percentage of the time do you feel fatigued?

3. Does your fatigue noticeably affect your daily physical and work routine?

4. Which issues do you also suffer from? Check each that applies to you:

Neurocognitive issues
Memory loss
Clumsiness
Difficulty concentrating or thinking
Non-refreshing sleep or sleep issues
Muscle or joint pains without swelling or inflammation
Headaches
Painful or tender lymph nodes
Frequent sore throat
Mental fogginess
Low blood pressure
Aggravated allergy symptoms – seasonal, food, environmental
Irritable bowel syndrome
Night sweats
Chronic or long-lasting cough
Palpitations or escalated heart rate
Recurring flu-like illness
Undetermined reasons for weight change

CFS diagnostic criteria (answers)

1. How long has your fatigue been present?

Fatigue must be present for six or more successive months. If it’s been present for less than six months, you likely have acute or subacute fatigue.

2. What percentage of the time do you feel fatigued?

You must feel fatigued for more than 50% of your day. If it’s less, other diagnoses need to be explored.

3. Does your fatigue noticeably affect your daily physical and work routine?

Yes – continue to next question

No – you do not have CFS and should have further tests to explain symptoms.

4. Which issues do you also suffer from?

You must have at least 4 of these symptoms occurring at the same time

Do You Have CFS with today’s criteria?

Now, remember, these questions are the old way of diagnosing CFS. The new way is more in-depth. Below is a similar questionnaire with the new diagnostic criteria that will tell you if you have SEID.

Just like you did in the previous sections, take out a pen and paper to answer the questions in order. After you’ve finished answering the questions, go through the answers located just below the questions.

SEID diagnostic criteria (questions)

1. Most of the time do you find it harder to work, socialize or take part in other activities due to your energy levels?

2. How long have you suffered from fatigue?

3. When did you begin to feel fatigued?

4. Is your fatigue the result of an ongoing exercise or fitness regime?

5. Does it improve when you get enough rest?

6. Do you feel more fatigue after exerting yourself??

7. Do you feel refreshed after sleep?

8. Do you suffer from one of the two symptoms?

A noticeable decline in cognitive abilities (ie: thinking, memory)
You don’t like standing upright

9. What percentage of the time do you feel fatigued?

SEID diagnostic criteria (answers)

1. Most of the time do you find it harder to work, socialize or take part in other activities due to your energy levels?

If you answered yes, this impairment needs to have occurred for more than 6 months.
If you answered no, you do not have systemic exertion intolerance disorder (SEID).

2. How long have you suffered from fatigue?

Fatigue needs to have occurred for more than 6 months.

3. When did you begin to feel fatigued?

Fatigue cannot be lifelong. There needs to be a definitive start point.

4. Is your fatigue the result of an ongoing exercise or fitness regime?

If you answered yes, this is not SEID
If you answered no, continue to the next question.

5. Does it improve when you get enough rest?

If you answered yes, your condition is not SEID.
If you answered no, continue to next question.

6. Do you feel more fatigue after exerting yourself??

If you answered no, your condition is not SEID.
If you answered yes, continue to next question.

7. Do you feel refreshed after sleep?

If you answered yes, your condition is not SEID.
If you answered no, continue to next question.

8. Do you suffer from a decline in cognitive abilities or an aversion to standing upright?

If you answered yes, you are positive for SEID
If you answered no, you do not have SEID

9. What percentage of the time do you feel fatigued?

You need to experience fatigue more than 50% of the time.

Your next steps towards a proper diagnosis

If your diagnosis came before 2015, I encourage you to book a follow-up appointment with your physician. Go through the new diagnostic procedures together. Make note of whether (or not) you still fit the diagnostic criteria.

If you no longer fit the diagnostic picture, be assertive. Ask your doctor to perform more testing that can help you identify the root cause of your fatigue. If your lab tests still come back within normal ranges, it’s time to find a knowledgeable functional medicine practitioner.

Now, I want to hear from you!’

Did the change in diagnostic criteria affect your diagnosis?

Do you really have CFS?

Do you need help improving your fatigue?

Want to know more than your doctor about fatigue? Click here to learn the best ways to achieve a clear, focused mind.