Whether or not an MRI can detect a problem when the headache is not present depends on the patient’s specific condition. If the headache is caused by pathologic factors, an MRI when the headache is not present can often detect the problem, whereas if the headache is physiologic, it may not be detected. If the headache is caused by pathological factors, such as intracranial space-occupying lesions, cerebrovascular diseases and intracranial infections, an MRI done when the headache doesn’t occur can detect the presence of intracranial tumors, ischemia, blockage of cerebral blood vessels or edematous changes caused by intracranial infections, which can assist in the diagnosis of the specific disease. Headache may also be caused by physiological factors, such as insufficient sleep, mental tension or excessive pressure. In this case, there are no organic lesions, and the MRI is often unable to detect the problem, regardless of whether the headache occurs or not. If headache occurs, after excluding physiological factors, the patient should consult the doctor in time, cooperate with the doctor to improve the examination program, identify the cause and treatment.