Is the duty of fasting waived for a sick person for whom fasting is difficult due to a chronic health condition that requires taking painkillers?

If the illness is expected to be cured, then the sick person should break their fast and make up the days they missed. If it is chronic and not expected to be cured, then they must break their fast and feed a poor person for each day, similar to someone who is unable to fast due to old age. Therefore, if the headache is chronic and you cannot fast with it except with great difficulty, and fasting increases it, then you must break your fast and feed a poor person for each day.