Why Does the Body Feel Weak While Fasting? Here Is the Medical Explanation

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KOMPAS.com - Fatigue during fasting is a common experience for many people, especially as the body adapts to changes in eating patterns and fluid intake during Ramadan. Internal Medicine Specialist at RS Pondok Indah, Dr. Ihsanul Rajasa, Sp.PD, FISQua, explains that fatigue during fasting is generally a natural response of the body to changes in meal timing. ‘Fatigue while fasting often occurs because the body is adapting to changes in eating patterns and fluid intake,’ Dr. Ihsanul said in an exclusive interview with Kompas.com on Wednesday (25 February 2026).

According to him, this condition is usually not dangerous provided it is not accompanied by signs of dehydration or other health disorders.

A temporary drop in blood sugar can make the body feel weaker than on ordinary days.

However, this condition remains a normal response as long as there is no significant impairment of bodily functions.

Some common signs include feeling slightly weak, light dizziness that improves after resting, and slightly reduced concentration but still able to carry out daily activities.

This condition generally does not last long and can improve approaching the time of breaking the fast.

‘With fasting durations ranging from 12 to 14 hours, it usually does not cause severe dehydration in the human body,’ Dr. Ihsanul explained.

For example, dizziness that becomes heavier, the body feels very weak, or signs of fluid deficiency appear.

If weakness is accompanied by signs such as very little urine or dark-coloured urine, the condition could indicate dehydration.

Ihsanul emphasises the importance of recognising the difference between normal bodily adaptation and signs of health problems.

By understanding the body’s signals from the outset, a person can determine whether the condition experienced remains normal or requires more attention.