Scholars agree

I'm ill. Can I stop fasting, and what do I owe afterwards?

Yes, and you do not need to be bedridden: it is enough that fasting would worsen the illness or slow your recovery. You make those days up when you are well. If the condition is chronic with no improvement expected, they are not made up: a poor person is fed for each day. The dispensation is in the text itself, not a later concession.

The four schools concur on this.

The long answer

The exemption for the ill person is stated alongside that of the traveller, and the reason for both is declared outright:

“Fasting for a limited number of days. So whoever among you is ill or on a journey during them - then an equal number of other days are to be made up. And upon those who are able to fast, but with hardship - a ransom as substitute of feeding a poor person each day. And whoever volunteers good i.e., excess - it is better for him. But to fast is best for you, if you only knew.” (Qur’an 2:184)

“The month of Ramaḍān is that in which was revealed the Qur’ān, a guidance for the people and clear proofs of guidance and criterion. So whoever sights the crescent of the month, let him fast it; and whoever is ill or on a journey - then an equal number of other days. Allah intends for you ease and does not intend for you hardship and wants for you to complete the period and to glorify Allah for that to which He has guided you; and perhaps you will be grateful.” (Qur’an 2:185)

What counts as illness enough:

  • A condition that fasting would genuinely worsen.
  • One that would make recovery slower.
  • A treatment requiring food or drink at fixed times.

You do not need to be in bed. Nor is a certificate required; the reference is your actual state, and in case of doubt, what a doctor says.

What you owe afterwards:

  • Temporary illness: you make the days up on recovery, without an anxious deadline, preferably before the next Ramadan.
  • Chronic illness with no expected improvement, or old age: they are not made up. For each day a poor person is fed (fidya).
  • If you begin the day fasting and worsen, you may break it; that day is made up.

Two things worth stating clearly. First: taking this dispensation is not a lesser version of Islam. It is following the instruction, and the verse ends by saying that Allah intends ease for you. Forcing a fast that is harming you is not piety.

Second: if you are unsure whether your case qualifies, that is a medical question before it is a religious one. Diagnosis first, ruling second.

What it rests on