Preparation for Prayer / Worship

Major impurities require ghusl (full body cleansing):

• discharge of semen coupled with lustful feelings, awake or at sleep
• sexual intercourse.
• menstrual period (haid),
• childbirth / postpartum bleeding
• death of a Muslim.
• embracing Islam

Minor impurities require wudu'

(washing hands, feet, face, mouth, nose, ears...):

• discharge of urine
• discharge of excrement
• discharge of wind
• sleep.
• being unconscious for any reason.
• touching one's private parts without a cover
• drunkenness

MISCELLANEOUS

"Touching a female without a cover, issue of blood from any part of the body, other than the two bottom openings, vomiting, touching a corpse, are sometimes included in constituting minor impurities.

A woman who suffers from continuous flow of blood, the person who suffers from flow of urine after urination, and the person who suffers from a constant escape of wind - all these people should make wudu for every Salat."

(Source: http://www.islam-mauritius.org/prayers/pptoc.htm)