Does swallowing phlegm or mucus break the fast?

Detailed answer

Phlegm or mucus that slides down your throat from your nose or chest without reaching your mouth does not break the fast. This happens naturally and you cannot avoid it. If the phlegm does come up into your mouth, the right thing to do is to spit it out rather than swallow it.

What scholars say

Phlegm is not food or drink, and it comes from inside the body, so it is treated differently from things taken in from outside. Scholars agree that phlegm swallowed without reaching the mouth, or swallowed without intending to, does not affect the fast. Allah says: "There is no blame on you for what you do by mistake, but only for what your hearts intend" (Al-Ahzab 33:5).

When phlegm has reached the mouth and someone swallows it deliberately, some scholars hold that the fast is broken, while others hold that it is not, though swallowing it is still disliked; if you are unsure, ask a trusted local scholar. Either way, spitting it out is the safe and clean choice.

In practice

• Keep tissues with you and spit phlegm out discreetly when it reaches your mouth.
• Do not worry about mucus that goes down the back of your throat on its own.
• Steam, warm drinks after iftar and sleeping with your head slightly raised can help reduce it.
• Saline rinses and sprays raise their own questions; see nasal spray and fasting.

If you are unwell

A mild cold usually does not stop someone from fasting. But if you have a fever, a chest infection or feel too weak, the Quran allows you to break the fast and make it up later: "Whoever of you is ill or on a journey, then an equal number of other days" (Al-Baqarah 2:184). Follow your doctor's advice, ideally a doctor who understands fasting, and read do I have to fast if I am sick.

For ordinary saliva, which never breaks the fast, see swallowing saliva while fasting.