Wa `alaykum as-Salamu wa rahmatullahi wa barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
I can read from what you wrote that you did really feel sick and for that it should be fine to break your fast and you only need to make up another day after Ramadan is done.
Responding to you question, Sheikh Kifah Mustapha, the Imam and Associate Director at the Mosque Foundation, one of the largest Islamic Centers in Chicago, states:
Allah Almighty said in the Qur’an, “…but one among you who is sick or is on a journey [shall then fast] the same number of other days” (Al-Baqrah 2:184)
As you can tell from the verse, it is very clear that you only need to make up for the days you missed.
Now, as to the level of sickness that allows someone to break his or her fast, you can see that the verse came open and did not specify what type of illness. Hence, a person can relate to his own health if he really felt sick or through a professional advice from a trustworthy physician.
In your case, I can read from what you wrote that you did really feel sick and for that it should be fine to break your fast and you only need to make up another day after Ramadan is done.
Having said this, we should also give a final note that illness effects are divided into three levels:
1- Illness that will cause harm for which you must break your fast.
2- Illness that is very mild in which breaking fast is not permissible.
3- Illness that is in between and causes discomfort and in this it is up to the person to fast or break the fast and make it up later.
Allah Almighty knows best.
Editor’s note: This fatwa is from Ask the Scholar’s archive and was originally published at an earlier date.