Fever at night and normal during the day is considered to be caused by inflammation. There are upper respiratory tract infections, digestive tract infections, urinary tract infections, etc., and parasitic infections. Because the fever will eat cold medicine, cold medicine often has antipyretic ingredients included, plus also eat anti-inflammatory drugs, so the condition during the day may control some, will not cause fever, often at night in sleep, did not take drugs, the concentration of drugs taken during the day, slowly decreasing, can not control the condition and fever, go to the hospital to check in order to better treatment. There is also a large amount of activity during the day, do not feel too comfortable also do not know in the fever, to rest at night to know in the fever, so will rush to use drugs, after taking the drugs, because the drug effect will last for a period of time, some up to 24 hours, to the day will not be fever, many people will not use drugs again during the day, to the next night, the drug effect is all gone, so will cause fever repeated. There are also parasitic infections, parasitic worms that come out day and night, which can also cause fever at night and not during the day. If fever occurs frequently, it is recommended to go to the hospital for further blood tests to find out the cause and then actively treat the cause.