Fasting is not just not eating or drinking but also our parts of our body must observe sawum.
Our eyes, ears and all other parts of our body. Here are a list of things that invalidate the fast if done on purpose
- Eating and drinking
- Saying false things to Allah, Prophet (s) or with the successors of the Holy Prophet(s).
- Making dust reach one's throat.
- Immersing one's head completely in water.
- Fast during the month of Ramadan of course
- Qaza fasts for the month of Ramadan
- Kaffara fasts
- Fast is broken or left out deliberately
On all days of Rajab, Shaban or any possible month to fast even it it's only a day or a week.
- Fasting during illness
- Fasting when travelling before salatul Dhuhr.
It is Makruh to fast in Ashura.
A person is allowed to break his fast that is Mustahab if it is not Qaza before Salatul Dhuhr.