Is it obligatory for a sick person who has recovered after an illness that caused her severe thirst due to medication to fast for the missed Ramadan, knowing that she is still taking thirst-inducing medications three times a day, and her illness is chronic but interspersed with periods of remission?

If the illness is hoped to be cured, then the days on which one broke their fast must be made up after recovery. However, if the illness is not hoped to be cured and causes unbearable hardship in fasting, then one must transition from making up the fasts (qada') to feeding the poor (it'am), as Allah Almighty says: "{And upon those who can afford it [but with difficulty] is a ransom: the feeding of a poor person}" (Quran 2:184). The reference for determining the type of illness is the physician.