Is one who fears increased weakness and fatigue due to fasting, in addition to facing extra hardship such as long daylight hours, studying, and working, obligated to fast, or is it permissible for them to break their fast and make up for it later?

It is permissible to break the fast in Ramadan for the sick person who is unable to fast or who fears an increase in their illness. If fasting causes a definite illness or physical harm due to emaciation and weakness, then breaking the fast is permissible with the requirement to make up the days when able. It is necessary to consult trustworthy doctors to assess this. However, mere fatigue and exhaustion are not excuses. Studying and working are not excuses for abandoning fasting, as it is one of the pillars of Islam.