Short answer
It depends on the purpose. Surgery to repair a defect, an injury, burns or the effects of illness is allowed. Surgery purely to look more beautiful than your normal, healthy features, such as reshaping a normal nose, breast or buttock enlargement, or a face-lift to look younger, is haram in the Hanafi school because it changes Allah's creation.
Reconstructive and corrective surgery for a real defect or harm is permissible. Purely cosmetic surgery on a normal body, for beauty or to look younger, is haram as changing Allah's creation, with the added harms of needless risk and uncovering the awrah.
The four schools agree on this.
Explanation
Ibn Mas'ud reported that Allah cursed women who tattoo, who pluck facial hair and who file their teeth for beauty, "changing the creation of Allah." Scholars take the key words to be for beauty and changing the creation: altering a normal, healthy body to make it more beautiful. The Quran also lists changing Allah's creation among the things Satan calls people to.
Repair is different. A Companion, Arfajah ibn As'ad, lost his nose in battle and made one of silver, which began to smell, so the Prophet ﷺ told him to make one of gold. Gold is normally forbidden for men, yet it was allowed to restore what had been lost. This is the basis for allowing surgery that brings the body back to normal.
Generally allowed:
- repairing a cleft lip or palate and other birth defects
- treating burns and scars from accidents or illness
- breast reconstruction after a mastectomy
- breast reduction to relieve real back pain or other physical harm
- correcting a deformity that causes real physical or serious psychological harm
Generally not allowed: reshaping a normal nose, lip, breast or buttock enlargement, liposuction or a BBL purely for shape, and face-lifts to look younger. The four schools share this principle, and contemporary scholars of all of them draw the line between treating a defect and enhancing a normal body.
Some cases fall in between, such as a feature that is far from normal and causes real distress. Take these to a mufti with your surgeon's assessment. For injectables, see lip fillers and Botox, and for hair loss see hair transplants.
Ask a mufti about your own case. This answer explains the general ruling. When the details of your situation matter, as they do here, ask a qualified mufti and give them the full facts. Where to ask a scholar.
The evidence
Quran, Surah An-Nisaa 4:119
وَلَأُضِلَّنَّهُمْ وَلَأُمَنِّيَنَّهُمْ وَلَءَامُرَنَّهُمْ فَلَيُبَتِّكُنَّ ءَاذَانَ ٱلْأَنْعَٰمِ وَلَءَامُرَنَّهُمْ فَلَيُغَيِّرُنَّ خَلْقَ ٱللَّهِ ۚ وَمَن يَتَّخِذِ ٱلشَّيْطَٰنَ وَلِيًّۭا مِّن دُونِ ٱللَّهِ فَقَدْ خَسِرَ خُسْرَانًۭا مُّبِينًۭا ﴿١١٩﴾
And I will mislead them, and I will arouse in them [sinful] desires, and I will command them so they will slit the ears of cattle, and I will command them so they will change the creation of Allah." And whoever takes Satan as an ally instead of Allah has certainly sustained a clear loss.
Changing Allah's creation for its own sake is something Satan calls to.
Quran, Surah At-Tin 95:4
لَقَدْ خَلَقْنَا ٱلْإِنسَٰنَ فِىٓ أَحْسَنِ تَقْوِيمٍۢ ﴿٤﴾
We have certainly created man in the best of stature;
The human form as Allah made it is already honoured.
Sahih Muslim 2125
Sahih... لعن الله الواشمات والمستوشمات والنامصات والمتنمصات والمتفلجات للحسن المغيرات خلق الله ...
"Allah has cursed the women who tattoo and have themselves tattooed, who pluck facial hair and have it plucked, and who file their teeth for beauty, changing the creation of Allah."
Altering a normal body for beauty is forbidden.
Sunan Abi Dawud 4232
Graded hasan... قطع أنفه يوم الكلاب فاتخذ أنفا من ورق فأنتن عليه ...
"Arfajah's nose was cut off in battle and he made a nose of silver, which began to smell, so the Prophet told him to make a nose of gold."
Restoring what has been lost is allowed, even using something normally forbidden.
Where the ruling is recorded
- Radd al-Muhtar (Ibn Abidin), Kitab al-Hazr wa al-Ibahah, Fasl fi al-Nazar wa al-Mass. Discusses the curse on changing the body for beauty and the difference between adornment and removing a defect.
- al-Fatawa al-Hindiyya, Kitab al-Karahiyya, chapter on treatment. Treating a defect or ailment of the body is permitted.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.