Will taking a blood test break my fast?

Answered by Shaykh Amjad Rasheed
Translated by Shaykh Hamza Karamali, SunniPath Academy Teacher

My doctor wants a sample of my blood to do some tests on me. Does it break my fast if he sticks a needle into my arm?

In the Name of Allah, Most Gracious, Most Merciful

In the Name of Allah, Most Merciful and Compassionate

The scholars of Sacred Law explain that one’s fast is invalidated if a substance reaches what is termed the “body cavity” (Ar. jawf). The “body cavity” refers to the head and the torso; one’s arms and legs do not count as part of the body cavity. [1] The entrance of a needle into one’s arm would therefore not invalidate one’s fast.

And Allah knows best.


[1] The books of the Shafi`i school explicitly state that the shins and thighs are not considered part of the body cavity (cf. Hashiyat al-Jamal). Shaykh Amjad Rasheed confirms below that the forearms and upper arms are analogous to the shins and thighs and are not considered part of the “body cavity” (Ar. jawf) in the Arabic language.


السؤال (1): صرحوا بأن الساق و الفخذ ليسا من الجوف المفطر وصول العين إليه فهل يلحق الساعدُ بالساقُ والعضد بالفخذ في عدم كونهما من الجوف ؟
الجواب : نعم يلحق الساعدُ والعضدُ بالساق والفخذ؛ في كونهما ليسا جوفاً فلا يفطر الصائم بوصول عين إليهما؛ لأنهما لا يسميان جوفاً ، والواجب على الصائم الإمساك عن وصول عين إلى ما يسمى جوفاً كما هي عبارة .”المنهاج”