There are basically 7 reasons for breaking ablution. Namely - one. Passing something through the toilet and urinary tract. Like air, urine, insects etc. Hidayah-1/7 It has been mentioned, If any of you urinates, (purify yourself to pray) Surah Mayida-6 Narrated by Hazrat Abbas (RA). Surely Rasulullah Sallallahu Alaihi Wasallam said, whatever comes out of the body, the ablution is broken because of it.... Sunan Kubra Lilbayahaki, Hadith No-568 two. Discharge of blood, pus, or water. Hidayah-1/10 When Hazrat Abdullah bin Umar (R.A.) had a nosebleed, he would go back and perform ablution. Muatta Malik-110 three. Vomit full of mouth. Narrated by Hazrat Aisha (RA). He said, The Messenger of Allah, peace and blessings be upon him, said, “Whoever vomits, Or bleeding from the nose, or muji (white water that comes out before intercourse), then go back and perform ablution. Sunan Ibn Majah, Hadith No. 1221 four. Equal or greater proportion of blood with sputum. Hasan Basri Rah. He said, whoever sees blood in his spit, then spit If the blood is not profuse, it is not necessary to perform ablution on it. Musannaf Ibn Abi Shaiba, Hadith No. 1330 five. Sleeping in a reclining position. Narrated by Hazrat Ibn Abbas (RA). Rasulullah Sallallahu Alaihi Wasallam said, if you sleep in the position of prostration Ablution does not break, but if you lie down, it will break, because if you lie down, the body becomes loose. [As a result there is a possibility of becoming an adulterer] Musnad Ahmad, Hadith No-2315, Sunan Abu Dawud, Hadith No-202 Six. If mad, drunk or unconscious. Hazrat Hammad (RA) Said, When a mad person recovers, he should perform ablution for prayer. Musannaf Abdur Razzaq, Hadith No. 493 Sat. Laugh out loud in prayer. Narrated by Hazrat Imran bin Hussain (RA). Rasulullah Sallallahu Alaihi Wasallam said that If a person laughs loudly in prayer, that person will repeat ablution and prayer. Hazrat Hasan bin Qutaiba (RA) said, When a person laughs out loud, that person will repeat ablution and prayer. Sunan Dara Qutni, Hadith No-612