Basal / Bolus- please explain!!

Basal/bolus is also known as MDI (multiple daily injections). The basal is the long acting insulin which is taken once a day or can be split in two to give a 24 hour coverage, the bolus is what you inject before eating food so is given 3 times a day if you eat breakfast, lunch and evening meal, typically bolus insulin's will last up to 5 hours after injecting depending on the type.