Headaches come in a vast array of forms, and can be symptomatic of yellow fever. Sharp, isolated pains and broad, dull aches. Untreated, they will often dissipate on their own. There are primary headaches, which are caused when there is too much activity in or around pain sensitive structures in the brain. These are commonly called tension headaches. Nerves or the blood vessels respond to chemical activity in the brain, which changes frequently.
Secondary headaches are symptoms of other biological dysfunctions such as hangovers, sinus infections and viruses. Most people have experienced headaches and understanding your personal history with them can help you decide if your symptoms are atypical. Since headaches can be symptoms of very serious malfunctions in the brain, even signs of impending stroke, always monitor the headache progression and see a doctor if the pain is unrelenting.