How drugs and alcohol affect the body
Biology · Key Stage 2 · The School
What a drug actually is
A DRUG is anything that changes how the body works, once it goes in. Some drugs are medicines. Doctors use them carefully to help the body. Other drugs are taken for other reasons. These can cause real harm, especially in large amounts. Knowing the difference matters a great deal. It can affect how safely a person makes decisions.
Legal and illegal drugs
Some drugs are LEGAL for adults. Alcohol is one. So is nicotine, found in cigarettes, though a 2026 law means shops will never be allowed to sell tobacco to anyone born on or after 1 January 2009. Other drugs are ILLEGAL — cannabis is one example. That means it is against the law to have them, or use them, at all, whatever your age. Being legal does not mean a drug is safe, though. The two ideas are simply not the same thing.
What alcohol does to the body
ALCOHOL slows down the brain. It affects balance. It affects speech too. It slows down how fast a person can react. That is why driving after drinking is so dangerous. It is also against the law. Too much alcohol, too often, can harm the liver over time. Some of these effects can be seen after just one drink.
Imagine a class is asked whether a cigarette pack from a UK shop is harmless. Step one: look at the pack. It has a written health warning. The UK government says on its website that the law requires one on all tobacco products. Step two: check the law on selling. Today, shops may sell cigarettes to adults born before 2009. A new law means shops will never be allowed to sell them to anyone born on or after 1 January 2009. That includes everyone in this class. Step three: check a trusted health source. The National Health Service says the longer-term risk of lung disease goes down when a person stops smoking. So smoking carries a risk of lung disease. Step four: fill in the check. Has a health warning: yes. Legal for shops to sell to some adults: yes. Linked to harm by the National Health Service: yes. So the class decides that legal does not mean harmless, as this pack shows.