There are many ways to classify how dangerous a drug is — its toxicity to the user, its addictive qualities, what impacts its use has on people’s behavior towards others (for example, whether it makes people more violent), or its overall negative impact on society at large, including the cost of hospital admissions and rehabilitation clinics. This article will focus on how deadly a particular drug is, in order from least to most deadly.

#5: Tobacco

Smoking kills up to 20% of the population prematurely, in a slow and painful fashion. Smokers die of lung disease, cancer of the lung and pancreas, emphysema, and arteries blocked by years of nicotine abuse.

Second-hand smoke can also cause cancer and other respiratory complaints among people who live or work in the vicinity of regular smokers. Yet tobacco is perfectly legal and readily available, in fact, vigorously promoted and sold in virtually every community.

Nicotine is highly addictive and is the legal drug of choice of many young people due to its relatively low cost compared to harder drugs and perceived “acceptability,” permitting them to become lifelong addicts of a commonly available drug at a very young age.

#4: Alcohol

Just because alcohol is legal in most countries doesn’t make it safe. It is also generally incredibly cheap, within easy reach of the majority of the population, including teenagers, so it is easy to establish a substantial drinking habit early in life which can develop into alcoholism later in life. Many alcoholics manage for many years to maintain a thin veneer of normality for the outside world.

Sadly, it is often close family members that have to deal with the abuse, violence and financial problems meted out by alcoholics. Oftentimes, they choose to leave the addict, unable to deal with the ongoing consequences of the addiction. Eventually, an alcoholic’s liver and kidneys can fail, killing them prematurely.

#3: Methamphetamine

The effects of methamphetamine or crystal meth have been likened to crack cocaine, but lasting considerably longer. Users can often stay awake for days on end, partake in marathon sessions of sex, or become incredibly violent while under the influence of crystal meth.

A neurotoxin, meth floods your brain with feel-good dopamine, but also damages the dopamine receptors, resulting in an insatiable desire for more meth. Health risks include increased likelihood of stroke, heart attack and psychosis, as well as participation in illegal and dangerous activities to fund a rampaging crystal meth habit.

#2: Heroin

Street names for heroin include horse, junk, skag, brown, smack and, of course, “H.” The biggest danger with heroin is the ease with which users can accidentally overdose and die. The lack of control of the purity of the drug, due to it generally being cut with other substances several times over leaves users in the dark as to how much to inject.

It also doesn’t take much to overdose. Psychologically, heroin is incredibly addictive and is one of the hardest drugs to give up. Many users will do just about anything to get their next fix, including partaking in highly risky activities, such as needle-sharing, prostitution and drug dealing.

#1: Cocaine

Also known as coke, charlie, crack, rock and blow, it is in the top three of the most addictive drugs in the world. Coke impacts the primal pleasure-seeking areas of the brain, which are normally triggered by eating delicious food or having sex, hence the powerful cravings for cocaine.

Few parts of the human body are not adversely affected by cocaine, with the biggest risks being strokes and heart attacks, which can both be fatal. Cocaine use results in more hospital emergency visits than any other illegal drug. In addition to the above risks from powdered cocaine, crack cocaine is harmful to your lungs and induces greater cravings in users and thus presents a greater risk of overdosing.

In conclusion, there are recreational drugs people can dabble in, and survive the experience relatively unscathed. But if you have an addictive personality and mess with any of the top five most deadly drugs, you are likely to wind up dead sooner, rather than later.