For sickness, a clear indicator is paleness of the skin... now this may raise argument but hear me out... I used to be quite pale- those were my times of dairy, meat & egg consumption.... I burned easily which is a sign of toxicity or mucus within ... so the pale or pallor skin is a sign of mucus buildup within from wrong foods... now that I've been on raw and mainly fruits for over 4 months, and on this health path for years, I do not burn and my skin tone has changed... I've proved this to myself and I learned it from various sources... health signs? Calmness, clear eyes (iridology reveals true health status)... white teeth, strong nails, the ability to think for oneself ... health is rare, sickness is commonplace... this is where humanity is at for now...