To give an example of the first type of people, a lot show signs like mental exhaustion, fatigue, stomach ache, reduced appetite, restless sleep, short-tempered, poor memory, flu-prone etc; but when they get examinations at the hospital, they found nothing at all, and get told they are healthy! If only that was true. People affected by things like these have an impaired life quality, being affected mentally and physically.

As for the second type, they might not suffer from discomforts or have any symptoms, but using modern day medical examinations they would fall in-between “healthy” and “unhealthy”; an example would be people who have early stage Type II diabetes, they might not have any discomfort nor symptoms that bother them. If they get their fasting blood sugar level checked they will see the anomaly but yet can not be diagnosed as diabetic (the threshold has not been met). This will qualify them as people with sub-health.