How many days does a fever usually last with Type A flu?
Feb 14, 2025
Source: Cainiu Health
Dr. Ren Yi
Introduction
Under normal circumstances, fever caused by influenza A usually lasts for 3–5 days; in children infected with influenza A, fever may persist for 5–7 days. If any discomfort occurs, seek immediate medical attention. Body temperature should be measured regularly, and it is recommended to use a mercury or electronic thermometer to measure axillary temperature. Generally, the temperature should be measured every 4–6 hours to accurately monitor temperature changes.
Generally, "swine flu" refers to influenza A. After infection with the influenza A virus, fever usually lasts for 3-5 days; in children, the fever may last for 5-7 days after infection. If discomfort occurs, immediate medical attention and treatment are necessary. Detailed analysis is as follows:
For most individuals with normal immune function, fever generally lasts for 3-5 days. After infection with the influenza A virus, the body's immune system responds quickly. Fever is a defense mechanism of the body that inhibits viral replication and spread by elevating body temperature. As the immune system gradually controls the virus, body temperature gradually returns to normal.
In children, the duration of fever after infection may be slightly longer, sometimes lasting 5-7 days. This is because children's immune systems are still developing and are relatively immature, making their ability to fight viruses weaker. Moreover, children's thermoregulatory centers are not as stable as those of adults, so fever may recur. Some young children may experience a drop in body temperature after taking antipyretic medication, but their temperature may rise again a few hours later.
Body temperature should be measured regularly. It is recommended to use a mercury thermometer or an electronic thermometer to measure axillary temperature. Generally, measurements should be taken every 4-6 hours to accurately monitor temperature changes. If body temperature exceeds 38.5°C and is accompanied by significant discomfort such as headache and muscle pain, antipyretic drugs may be considered.
