Things that break the fast:
1- Eating and drinking
2- Intercourse
3- Menstruation and nifaas
4- Vomiting deliberately
5- Letting blood by means of cupping and the like. There is a difference of opinion on this issue as there are narrations which show the Prophet stating the invalidating of the cupping person and other narrations which show that Prophet had it done whilst he was fasting and in the state of Ihram.
The things that invalidate the fast are of two types; that which enters or leaves the body. The first type of things that invalidate the fast involve things entering the body, such as eating and drinking.
The second type of things that invalidate the fast involve things coming out of the body, such as during intercourse, deliberate vomiting, menstruation etc. These things that come out of the body weaken it. Hence, Allah has described them as being things that invalidate the fast, so that the fasting person will not combine the weakness that results from fasting with the weakness that results from these things, and thus be harmed by his fast or his fast no longer be moderate.
Things that do not break the fast
1- Accidentally eating or drinking,
2- Bleeding [unintentionally]
3- Wet dream [although ghusl must still be done]
4- Vomiting [as long as it is not deliberately]
5- Using Miswak [toothbrush]
6- Using Perfume
8- Applying Perfume/Attar
9- Sleeping whilst fasting