relapse
n.a time when someone gets sick again after they seemed to be getting better. It is also used when someone starts a bad habit again after they had stopped.
n.a deterioration in health after a period of improvement; the recurrence of a disease or a return to addictive behaviour.
“He was doing well, but he suffered a relapse last week.”
“The doctor warned that stopping the medication too early could lead to a sudden relapse of the infection.”
“While the initial recovery was promising, the patient experienced a minor relapse during the third month of treatment, necessitating a more aggressive therapeutic intervention.”
Often used with the verbs 'suffer', 'have', or 'experience'.
“I was able to put aside the walking stick (at least between relapses) and resume typing my long overdue PhD thesis.”
“This finding suggests it might be possible to identify people who are at risk of relapsing by screening for BNST activity when someone is given access to alcohol.”
From Latin relapsus, past participle of relabi (“to slide back, fall back”), from re- (“back”) + labi (“to slip, slide, fall”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.