The large majority of people living in westernized cities/communities have some form of illness, more than one illness usually, too.
I think the determinants of what makes a health condition bearable or unlivable depend on how much function you have in life; can you walk, exercise, socialize, maintain employment, eat food/drink water without assistance and live independently? Or are you crippled by your symptoms? So crippled that you are locked in the house, unable to leave, even despite a visceral yearning to reintegrate with the world and become functional again.
A lot of people are able to "fake" wellness, and if you're well enough to construct a facade everyday without it sending you into a crippled, bed-ridden/worsening state of health, then I'd say you've got enough function to have a half miserable and half rewarding life.
I cannot fake wellness to anyone, it's screamingly obvious that I am very sick, and I require help (that I am not able to pay for) in order to just make myself a meal or even fall asleep at night. I have none of the vital bodily functions working properly that are necessary to fake a normal level of health.
I'm being tortured every moment of the day because my symptoms are so merciless and unrelenting. The absolute state of my body right now is torturous, but the future for me is looking even more ghastly than it feels now, and I can't even comprehend how the human body has no ceiling when it comes to unconscionable suffering, but when it comes to tremendous pleasure, it's designed to be ephemeral and forgettable when compared to the day-to-day violence that the body is capable of self-inflicting without any malevolent stimuli.