As soon as you begin to understand that everything in this universe is connected, you will easily be able to understand that everything, impacts everything. Starting from the shows you watch, the music you listen to, the foods you eat, the people you surround yourself with... I could go on forever. When you have a head ache, you usually medicate, sleep, put an ice pack on your head, etc. You may even hold your head or press on your temples. This is your body telling you, you may or may not be dehydrated, you need to get some sleep, you need to eat, or you need a study break. Your body is always communicating with you, and this leads us into our very first chakra, which is the crown chakra. The crown chakra is violet, located at the top of your head, and this represents your spirituality and awareness of the body. When you get that head ache, it's telling you all the things I previously mentioned and letting you know that more energy needs to be focused on your head.
Moving down, there is the third eye chakra. This chakra is indigo, located right in-between your two eyes, and this chakra represents seeing the bigger picture and focus.