First symptoms of food poisoning

Food poisoning is an illness caused by contaminated food or drink. Symptoms may begin soon after exposure or later, depending on the germ or toxin involved. Nausea and cramping can come before vomiting or loose stools. Several symptoms together can drain water and salts from the body, causing thirst, a dry mouth, dizziness, weakness, or passing less urine. Symptoms can overlap with other stomach illnesses, so the pattern and its progression matter.

Take small, frequent sips of water or an oral rehydration solution, especially after vomiting or each loose stool. Rest, and eat light foods when you feel able; avoid alcohol and foods that clearly worsen nausea. Wash your hands with soap and water and avoid preparing food for other people while you are unwell. Oral Rehydration Therapy can help replace fluid and salts. Severe dehydration may require IV Fluid Therapy in a clinical setting.

Seek urgent medical help for fainting, confusion, severe or worsening abdominal pain, blood in vomit or stool, inability to keep fluids down, or signs of marked dehydration. A high fever, symptoms after eating seafood or mushrooms, or illness in a baby, older adult, pregnant person, or someone with a long-term condition also merits prompt advice.

Ask which fluids are suitable, whether any medicines should be avoided, and what changes would mean you need an examination. Tell the clinician when symptoms began, what you ate, whether anyone else is ill, and how often you have vomited or had diarrhoea.