Chance of infection — This is generally a twofold major concern: Needle sharing or sharing syringes may transmit blood-borne diseases between users, such as HIV-AIDS and Hepatitis C Abscessed infections of injection sites are caused by lack of proper hygiene and a lack of aseptic technique during the injection process. Increased chance of overdose[2] — Because IV injection delivers a dose of drug straight into the bloodstream, it is harder to gauge how much to use (as opposed to smoking or snorting, where the dose can be increased relatively incrementally until the desired effect is achieved; this gives a user who is in danger of overdosing a chance to seek medical treatment before respiratory arrest sets in). In addition, because of the rapid onset of intravenous drugs, overdose can occur very quickly, requiring immediate action.