Which of the following is a common symptom of foodborne illness?

Nausea is a common symptom of foodborne illness and often serves as an early warning sign that something is wrong after consuming contaminated food or beverages. When harmful bacteria, viruses, or parasites affect the gastrointestinal system, they can stimulate the vomiting reflex, leading to feelings of nausea. This symptom arises from the body's efforts to expel the toxins or pathogens it has ingested, which can also be accompanied by other gastrointestinal symptoms such as vomiting, diarrhea, and abdominal cramps. Recognizing nausea as a key symptom helps in identifying foodborne illness and seeking prompt medical attention if necessary.

While headache, blurred vision, and fatigue can be associated with various health issues, they are not as directly linked to the ingestion of contaminated food.