A drug is any chemical substance that can change the way your body works and the way you feel. There are lots of different kinds of drugs, some legal and some illegal, each with a different effect. Some drugs are taken for medical reasons, and some drugs are taken for recreational reasons.
No drug is completely safe. Every drug - legal or illegal - can have a negative effect on your health. This is particularly true when it comes to illegal drugs. The manufacture of legal drugs is closely monitored, but there are no controls over what goes into illegal drugs. You never really know what you're taking.
Types of drugs and their effects
Drugs generally fall into three categories:
Depressants - These drugs slow down messages to and from your brain. Depressants include heroin, morphine, valium, marijuana and alcohol. Large amounts of depressants can make you pass out, vomit or even stop breathing.
Stimulants - These drugs speed up the messages going to and from your brain. Stimulants include caffiene, nicotine, speed, ice, ecstasy and cocaine. Using stimulants can increase your body temperature, reduce your appetite, make you anxious and paranoid, and can put a strain on your heart.
Hallucinogens - These drugs change your perception of reality. Hallucinogens include LSD, magic mushrooms, mescaline and ecstasy (high doses of cannabis can also cause hallucinations). Taking hallucinogens can cause anxiety and paranoia, make you take risks you normally wouldn't, and can also cause psychosis.
A drug's effects can depend on things like your size, weight, height or what other drugs you've taken. If you take a drug a lot it can also have an effect on how that drug affects you. It also depends on how much you take.
Because illegal drugs are uncontrolled, it's hard to know exactly how much you're taking. The quality and strength of any illegal drug can be completely different each time you take it.
Mixing drugs - including alcohol - is also dangerous because it puts stress on your body and can cause serious health issues, especially if you mix drugs frequently. For example, mixing different kinds of depressants can lead to overdosing, and mixing stimulants puts additional strain on your heart.
Drugs can also mess up your judgement, making you do things - including dangerous and life-threatening things - that you wouldn't otherwise do. To find out more about the effects of specific drugs, check out:
There are other risks related to the use or overuse of drugs, both legal and illegal, besides the risk to your mental and physical health.
Drugs and pregnancy
Using any drugs while pregnant can seriously affect the health of unborn children - for more information about drugs and pregnancy check out DrugInfo's Pregnancy, Alcohol and Other Drugs page (new window)
Drugs and driving
Driving after taking drugs can seriously affect your driving ability, increasing the chance of an accident - for more information about drugs and driving, check out the Vicroads Alcohol and other drugs pages (new window)
Sharing needles dramatically increases the risk of HIV, Hepatitis and other transmissable diseases - Check out theDepartment of Health's Needle and Syringe Programs page (new window) for more information about needle exchanges, and the Australian Federation of AIDS Organisations (new window) for more about safe needle use.