What words refer to recovering?

recover, get better, make a slow/quick/complete recovery, get well, feel better, improve, be on the mend, respond to treatment, regain your health, gain strength, make good progress,

What words refer to no longer being very sick?

out of danger,

What words refer to being healthy after being sick?

be better, be well, be fully recovered, be cured, be over something, be back on your feet, be up and about, be fit, be healed, be well again, be fine, be back to normal, be restored to health, be whole again,

What words refer to a disease going away?

go away, clear up,