Nausea, vomiting and general weakness are likely to be caused by gastrointestinal insufficiency, which can be caused by diseases such as acute gastroenteritis, gastrointestinal flu and gall bladder disease. Patients can recall whether they have been eating regularly and with cleanliness and hygiene recently. In addition to this, there may be systemic diseases such as low blood potassium and sodium and anaemia. It is therefore necessary to have various tests such as a temperature check to identify the cause of this condition.