Although a mild cold does not affect the quality of the blood, it is medically necessary to avoid the possibility of the presence of influenza virus in the blood. Infection with the flu virus can have a significant impact on the quality of blood and can easily lead to the spread of the flu virus, which can lead to an increase in white blood cells and a decrease in the resistance of the recipient, which may aggravate the condition of the recipient. The body needs enough energy and strength to restore the blood content after blood donation. If you donate blood during a cold, your resistance will be weakened and you will easily aggravate your cold. If you have a cold, you need to actively treat it with medication, such as aminophenol pseudo-lax dispersible tablets or cold and fever granules. It is safer to wait for a week after you have fully recovered from the cold before donating blood, which is also good for your health.