Keto flu fever: what should you know?

Keto flu is a name for temporary symptoms that can occur as the body adapts to a very low-carbohydrate eating pattern. People may report headache, tiredness, dizziness, nausea, muscle cramps or irritability. These symptoms can relate to changes in fluid and salt balance, reduced carbohydrate intake, or eating too little.

Feeling warm or having chills can happen for several reasons, but a measured raised temperature is different from fatigue or flushing. Fever is the body's response to an underlying process, often an infection. A fever alongside cough, sore throat, vomiting, diarrhoea, painful urination, a rash or localised redness deserves attention because these symptoms can occur with illnesses such as a common cold, COVID-19, cellulitis or chickenpox.

Check your temperature with a reliable thermometer and record the reading with the time and any other symptoms. Rest, drink fluids, and avoid strenuous exercise while you feel unwell. Do not assume that increasing salt or taking supplements will treat a fever; medicines and electrolyte products may be unsuitable with kidney, heart or blood-pressure problems.

If symptoms began after changing your diet, consider pausing the restrictive plan and eating a balanced, tolerable meal pattern until you have advice. A clinician can review your medicines, hydration, medical conditions and the reason for the temperature. Do not stop prescribed treatment without guidance.

Arrange prompt medical advice for a fever that persists, returns, or is accompanied by worsening pain, repeated vomiting, confusion, marked weakness, breathing difficulty, a stiff neck, a spreading rash, or inability to keep fluids down. Seek urgent help for severe breathing trouble, fainting, new confusion, or a rapidly worsening condition.

Children, older adults, pregnant people, and anyone with reduced immunity or a long-term condition may need earlier assessment. A healthcare professional can determine whether the temperature reflects an infection, dehydration or another problem rather than diet adjustment.

Ask: How should I confirm whether this is a fever? Could my medicines or medical conditions make a ketogenic diet unsafe? Which fluids or foods are appropriate for me? What symptoms should prompt same-day care?