مَا يُصِيبُ الْمُسْلِمَ مِنْ نَصَبٍ وَلَا وَصَبٍ وَلَا هَمٍّ وَلَا حَزَنٍ وَلَا أَذًى وَلَا غَمٍّ حَتَّى الشَّوْكَةِ يُشَاكُهَا إِلَّا كَفَّرَ اللَّهُ بِهَا مِنْ خَطَايَاهُ
Ma yusibu al-Muslima min nasabin wa la wasabin wa la hammin wa la hazanin wa la adhan wa la ghammin hatta ash-shawkati yushakuha illa kaffarAllahu biha min khatayah
No fatigue, illness, anxiety, sadness, harm, or distress befalls a Muslim — even the prick of a thorn — except that Allah expiates some of his sins because of it.
Not a du'a but a promise — and one of the most comforting hadiths for the sick. Six types of suffering are listed, from serious illness down to a tiny thorn prick. Nothing is wasted. Every ache, every worry, every moment of discomfort is converting sins into expiation. The math is always in your favor: temporary pain for permanent forgiveness. The believer who is sick and patient is winning on two fronts.
Related Du'as
أَسْأَلُ اللَّهَ الْعَظِيمَ رَبَّ الْعَرْشِ الْعَظِيمِ أَنْ يَشْفِيَكَ
I ask Allah the Almighty, Lord of the Mighty Throne, to cure you. (Say seven times.)
Sahihلَا بَأْسَ طَهُورٌ إِنْ شَاءَ اللَّهُ
No worry, it is a purification, if Allah wills.
Sahihاللَّهُمَّ اشْفِنِي شِفَاءَكَ وَدَاوِنِي دَوَاءَكَ وَعَافِنِي مِنْ بَلَائِكَ
O Allah, heal me with Your healing, treat me with Your cure, and grant me well-being from Your trial.
Hasanاللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْبَرَصِ وَالْجُنُونِ وَالْجُذَامِ وَمِنْ سَيِّئِ الْأَسْقَامِ
O Allah, I seek refuge in You from leprosy, madness, elephantiasis, and all severe diseases.
Sahih