A headache occurs in the third trimester of pregnancy and is quite intense. First of all, it is recommended to take the body temperature to see if there is any fever causing the headache. Secondly, if there is no fever and other symptoms, it is better to go to the neurology department of a regular hospital to check the nature of the headache, have the doctor measure the blood pressure, and determine the general situation according to the nature of the headache, such as fluctuating pain or vague pain. If the test result is normal, you can take some oral pain medication and nerve regulating medication for treatment.