Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
muslim:2586c – Abū Bakr b. Abū Shaybah And ʾAbū Saʿīd al-Ashaj > Wakīʿ > al-Aʿmash > al-Shaʿbī > al-Nuʿmān b. Bashīr

The believers are like one person; if his head aches, the whole body aches with fever and sleeplessness.  

مسلم:٢٥٨٦c – حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ وَأَبُو سَعِيدٍ الأَشَجُّ قَالاَ حَدَّثَنَا وَكِيعٌ عَنِ الأَعْمَشِ عَنِ الشَّعْبِيِّ عَنِ النُّعْمَانِ بْنِ بَشِيرٍ قَالَ

قَالَ رَسُولُ اللَّهِ ﷺ الْمُؤْمِنُونَ كَرَجُلٍ وَاحِدٍ إِنِ اشْتَكَى رَأْسُهُ تَدَاعَى لَهُ سَائِرُ الْجَسَدِ بِالْحُمَّى وَالسَّهَرِ  

See similar narrations below:

Collected by Aḥmad, Suyūṭī
ahmad:18355 – Abū Muʿāwiyah > al-Aʿmash > al-Shaʿbī > al-Nuʿmān b. Bashīr

[Machine] The Messenger of Allah ﷺ said, "The example of a believer is like the example of a body. When one part of the body complains, the rest of the body responds with sleeplessness and fever."  

أحمد:١٨٣٥٥ – حَدَّثَنَا أَبُو مُعَاوِيَةَ عَنِ الْأَعْمَشِ عَنِ الشَّعْبِيِّ عَنِ النُّعْمَانِ بْنِ بَشِيرٍ قَالَ

قَالَ رَسُولُ اللهِ ﷺ مَثَلُ الْمُؤْمِنِ كَمَثَلِالْجَسَدِ إِذَا اشْتَكَى الرَّجُلُ رَأْسَهُ تَدَاعَى لَهُ سَائِرُ جَسَدِهِ  

ahmad:18433 – Wakīʿ > al-Aʿmash > al-Shaʿbiyyiʿan al-Nuʿmān b. Bashīr

The believers are like one person; if his head aches, the whole body aches with fever and sleeplessness. (Using translation from Muslim 2586c)  

أحمد:١٨٤٣٣ – حَدَّثَنَا وَكِيعٌ حَدَّثَنَا الْأَعْمَشُ عَنِ الشَّعْبِيِّعَنِ النُّعْمَانِ بْنِ بَشِيرٍ قَالَ

قَالَ رَسُولُ اللهِ ﷺ الْمُؤْمِنُونَ كَرَجُلٍ وَاحِدٍ إِذَا اشْتَكَى رَأْسُهُ تَدَاعَى لَهُ سَائِرُ الْجَسَدِ بِالْحُمَّى وَالسَّهَرِ