Can viral flu cause fever?

Fever generally refers to an elevated body temperature. Viral colds can indeed cause fever symptoms. The cause of fever may be the virus itself invading the human body, leading to increased body temperature; alternatively, after viral invasion, infection occurs and toxins produced by the virus are absorbed into the body, which can also lead to systemic discomfort symptoms such as fever. All these situations require symptomatic management.

1. Fever caused directly by the virus

After entering the body, viruses release endotoxins and generate pyrogens, which induce fever. Additionally, viruses may act on the body's thermoregulatory center, causing dysfunction of this center and shifting the body's temperature set point, resulting in increased heat production and reduced heat dissipation—thus triggering fever. In such cases, symptomatic treatment is required. For high fever, non-steroidal anti-inflammatory drugs (NSAIDs), such as acetaminophen, may be taken orally under medical guidance to reduce fever. For the viral infection itself, antiviral treatments such as cold-relief granules may be used.

2. The body's immune response

When a virus invades the body and non-specific immunity fails to counteract it, specific immunity is activated. T lymphocytes specifically bind to the virus and release substances that lyse the virus. Phagocytes then engulf the destroyed viral particles and cellular debris. This phagocytic process is exothermic and may trigger a systemic fever response.

Fever is a protective mechanism of the body against viral invasion. If a viral cold causes fever, timely antiviral treatment is recommended to prevent worsening of the condition.