Even though it is a very common problem among some people, scientists have no clear explanation as to why some perfumes cause headaches. Also, not everybody might get a headache because of the same scent. One assumption is that this type of headache is psychological. So, there might not be a clear scientific reason. But scientists also suggest that some chemicals in some perfumes can cause the blood vessels to dilate and increase the blood pressure. When this happens, the person might feel a headache for a short period of time.