How quickly does food poisoning start?

It depends on the cause. Some bacteria cause symptoms within hours; others take days. If several people become ill after the same meal, food poisoning is more likely than a stomach virus caught from another person.

How long does food poisoning last?

Most people feel better within two to three days. Diarrhoea can occasionally last up to a week. See a GP if symptoms persist or worsen.

What is the best treatment for food poisoning?

Rest and frequent small sips of water or oral rehydration solution. Eat plain food when you can tolerate it. Avoid anti-diarrhoea medicines unless a pharmacist or doctor advises them — they can sometimes prolong illness.

Do I need antibiotics for food poisoning?

Most food poisoning is self-limiting and does not need antibiotics. Some specific bacterial causes may need antibiotics — a GP decides this based on symptoms and sometimes stool tests.

How can I prevent food poisoning at home?

Wash hands before handling food, cook meat thoroughly, store food at correct temperatures, do not leave cooked food at room temperature for long, and use separate boards for raw meat. Check use-by dates.

Food poisoning | HealthAnswers

Quick answer

What is food poisoning?

Food poisoning is illness caused by eating food contaminated with harmful bacteria, viruses or parasites. Symptoms include diarrhoea, vomiting and stomach cramps, usually starting within hours to days of eating affected food. Most people recover within a few days with rest and fluids — seek help if you cannot keep fluids down or have signs of dehydration.

What is food poisoning?

Food poisoning is illness caused by eating food or drink contaminated with harmful bacteria, viruses, parasites, or their toxins. It causes inflammation of the stomach and gut, leading to vomiting, diarrhoea and stomach cramps. Most cases are unpleasant but short-lived.

Food poisoning is different from catching a stomach bug from another person — though the symptoms can feel similar.

Symptoms

Food poisoning symptoms often come on suddenly and may include:

nausea and vomiting
watery or bloody diarrhoea
stomach cramps and pain
a high temperature
headache and general weakness

Symptoms may start within hours of eating contaminated food (for example with toxins from Staphylococcus) or take several days (for example with Salmonella or E. coli). The timing can help identify the cause.

Common causes

Contamination can happen at any stage — production, storage, cooking or serving:

Undercooked meat — especially chicken, mince and burgers
Raw or undercooked eggs — in homemade mayonnaise or desserts
Unpasteurised milk and cheese
Food left at room temperature too long — buffets, picnics, reheated rice
Cross-contamination — raw meat juices on surfaces or utensils
Shellfish and raw fish — if not fresh or stored properly

Recovering at home

Most people manage food poisoning at home:

Fluids — sip water or oral rehydration salts frequently; small amounts are better than large gulps if vomiting.
Rest — avoid strenuous activity while unwell.
Plain food — reintroduce toast, rice, bananas and soup when you can keep fluids down.
Avoid — alcohol, caffeine, fatty or spicy food until fully recovered.

Do not take anti-diarrhoea medicines unless advised — they can trap bacteria in the gut.

When to see a GP

Contact NHS 111 or a GP if you cannot keep fluids down, have blood in vomit or stool, symptoms last longer than expected, or you are in a vulnerable group (baby, older adult, pregnant, weakened immune system).

Do not visit a GP surgery in person while actively infectious — call for advice first.

Reporting food poisoning

If you suspect food poisoning from a restaurant, takeaway or shop, report it to your local environmental health department. They investigate outbreaks and can prevent others becoming ill. Keep any leftover food refrigerated in case it needs testing.

Food poisoning vs norovirus

Norovirus spreads easily from person to person and is a common cause of gastroenteritis — not always linked to a specific meal. If you ate something that many others also ate and became ill, food poisoning is more likely. Both are managed similarly with fluids and rest.

Prevention

Safe food handling at home significantly reduces risk: wash hands, cook meat thoroughly, chill food promptly, and never reuse boards or knives for ready-to-eat food after contact with raw meat.

Common questions

How quickly does food poisoning start?: It depends on the cause. Some bacteria cause symptoms within hours; others take days. If several people become ill after the same meal, food poisoning is more likely than a stomach virus caught from another person.
How long does food poisoning last?: Most people feel better within two to three days. Diarrhoea can occasionally last up to a week. See a GP if symptoms persist or worsen.
What is the best treatment for food poisoning?: Rest and frequent small sips of water or oral rehydration solution. Eat plain food when you can tolerate it. Avoid anti-diarrhoea medicines unless a pharmacist or doctor advises them — they can sometimes prolong illness.
Do I need antibiotics for food poisoning?: Most food poisoning is self-limiting and does not need antibiotics. Some specific bacterial causes may need antibiotics — a GP decides this based on symptoms and sometimes stool tests.
How can I prevent food poisoning at home?: Wash hands before handling food, cook meat thoroughly, store food at correct temperatures, do not leave cooked food at room temperature for long, and use separate boards for raw meat. Check use-by dates.

Sources

NHS — Food poisoning