I would define health as the ability to perform normal daily function without aid. If someone can walk up the stairs on their own, make food for themselves, and think for themselves, that individual is in general healthy. While I do believe there is varying levels of health per individual, I believe being able to perform simple daily tasks in order to live make an individual healthy. Illness is the inability to perform these functions. While one might not categorize a disability as an illness, under my definition they cannot perform daily tasks on their own (depending on the disability). My understanding of health and illness is based on my own life. When I can get out of bed and do everything I need to in a day, whether or not I am sick, I do not feel like I am ill and I feel like I am a healthy individual. If I’m stuck in bed or need to go to the hospital, I am not healthy.
I do believe sadness is a symptom of many illnesses, but it is not an illness itself. It is an emotion we all feel. With the growing number of mental health issues being diagnosed these days, I feel like sadness plays a large part in it. Are you sad? Well are you depressed, anxious, or are you having trouble performing a task? Those are the issues a physician may ask their patient while understanding their state of mental health.
Anxiety is an illness in my opinion. When an individual suffers from anxiety, it is extremely difficult to perform many tasks. Your brain wanders and worries about the silliest things, causing you to lose focus on your goals. Individuals suffering from anxiety seek counseling or medication to alter their perception. Xanax and other medications (while given out too liberally) help those individuals with anxiety perform regular daily functions.