Health

A drug is a substance that changes the way your body or mind works. Medicinal drugs treat or prevent illness: paracetamol for pain, antibiotics for bacterial infections, inhalers for asthma. Recreational drugs are taken for their effect on the mind. Caffeine, nicotine and alcohol are legal, but in the UK only adults can buy alcohol, tobacco and nicotine vapes. Many other drugs are illegal.

The law on smoking and vaping. Under the Tobacco and Vapes Act 2026, from 29 October 2026 you must be 18 to buy any vape, even one with no nicotine in it, or nicotine pouches. From 1 January 2027 it is illegal to sell tobacco to anyone born on or after 1 January 2009, however old they are: if that is you, nobody will ever be allowed to sell you cigarettes. The aim is a smokefree generation.

Type	What it does	Examples
Stimulant	Speeds up the nervous system: more alert, faster heart rate	Caffeine, nicotine
Depressant	Slows down the nervous system: slower reactions	Alcohol, solvents
Painkiller	Reduces pain	Paracetamol, ibuprofen

Many drugs are addictive: the body comes to depend on them, and stopping brings unpleasant withdrawal symptoms. Drug misuse means using a drug in a harmful way: too much, too often, or a medicine not as prescribed. Sniffing solvents such as glue or aerosols can kill, even the first time.

In tobacco smoke	What it does
Nicotine	An addictive stimulant. Raises the heart rate and blood pressure
Tar	Sticky; coats the airways and alveoli, damages the cilia, and contains chemicals that cause cancer
Carbon monoxide	A poisonous gas that takes the place of oxygen in red blood cells, so less oxygen reaches the body

Smoking causes lung cancer, heart disease, bronchitis and emphysema (damaged alveoli, so less surface for gas exchange). Smoking in pregnancy means less oxygen for the baby, which may be born early or small. Passive smoking harms the people nearby. Vapes have no tar, but most contain addictive nicotine, and they are not harmless.

Alcohol is a depressant. In the short term it slows reactions and harms judgement, balance and speech. Over years, heavy drinking damages the liver (cirrhosis) and the brain, and causes heart disease and some cancers. Units of alcohol = strength (%) × volume (ml) ÷ 1000. A 500 ml beer at 4% holds 4 × 500 ÷ 1000 = 2 units. UK doctors advise adults not to regularly drink more than 14 units a week, say an alcohol-free childhood is the healthiest option, and advise no alcohol at all in pregnancy.

Check the evidence. Real medicines are tested in fair trials before doctors can use them. A “miracle cure” that has never been tested, sold from the back of a wagon, is called quackery.