Functional Medicine (5 Tests)

When fatigue that rest does not relieve lasts more than a month, we first check common causes with basic blood tests such as anemia, thyroid, liver and kidney function, blood sugar, inflammation markers, vitamin D and iron. We also consider lack of sleep, sleep apnea, low mood and current medicines as causes.

If basic tests show no clear cause, functional medicine tests that look at nutritional metabolism, such as a urine organic acid test, can be added as supporting information. These tests do not diagnose disease, so the results are interpreted alongside lifestyle care.

See blood tests →

Chronic fatigue syndrome is severe fatigue lasting more than six months that rest does not relieve, worsens after even small exertion, leaves sleep unrefreshing and comes with poor memory or concentration. It is diagnosed only after other causes of fatigue have been ruled out.

Most everyday fatigue has another cause, so we look for it first and refer you to a sleep clinic, psychiatry or neurology when needed.

Treatment centers on the cause found through testing. If tests point to an underlying condition such as anemia, an underactive thyroid or abnormal blood sugar, we treat that condition and watch whether the fatigue improves along with it.

For fatigue with no clear cause, the foundation is everyday habits: going to bed and getting up at consistent times, pacing your activity to what your body can handle, and cutting back on caffeine and alcohol. If testing shows a nutritional deficiency, supplements or an IV may be added as supportive care after a consultation, but an IV does not replace treating the cause.

Brain fog describes feeling mentally hazy, having trouble concentrating and forgetting things more often. It is not a diagnosis but a symptom with many possible causes. Common ones include lack of sleep, anemia, an underactive thyroid, low vitamin B12, depression and anxiety, menopausal changes, medications that cause drowsiness, and recovery after COVID-19.

That is why treating brain fog starts with a consultation and blood tests to find the cause, and what comes next depends on what we find. If you suddenly have slurred speech, weakness in an arm or leg on one side, or confusion, it may be an emergency such as a stroke. Call 119 right away.

A urine organic acid test usually uses the first morning urine and analyzes organic acids that reflect energy metabolism and nutritional status. Results come back from an outside lab and serve as a reference when planning supplements or IV formulas.

Besides energy metabolism and nutritional status, organic acid analysis looks at markers related to how neurotransmitters are made, liver detoxification and the gut environment. Food and supplements taken before the test can affect the results, so letting us know which supplements and medications you take helps us interpret them.

Functional medicine is an approach that looks beyond a single diagnosis or symptom to how factors such as nutrition and metabolism, the gut environment, stress and sleep affect the way the body functions. Integrative functional medicine is a term for using this approach alongside conventional care, and it does not replace standard diagnosis and treatment.

The value of these tests is not that the test itself makes you better, but that the results help set a concrete plan for diet, sleep and nutritional support.

Korea has no specialist certification in functional medicine. Specialist status exists only for specialties defined by law, such as internal medicine and family medicine, and functional medicine is a field that doctors from various specialties learn through society training and other programs and use alongside their practice. VEI Clinic's medical director is an internal medicine specialist and a full member of the Korean Institute of Functional Medicine.