Chronic headaches that last for days are most commonly tension headaches. Tension headaches occur when neck and scalp muscles become tense, or contract. The muscle contractions can be a response to stress, depression, a head injury, or anxiety. Other causes are- too much caffeine or its withdrawl, eye strain and fatigue. A headache diary may help you to identify and avoid your headache triggers. Please note down the day and time the pain begins. The diary must include notes about what you ate and drank around the time when the headache started last, how much you slept and when, and the your routine immediately before the pain started. You can figure out if you had any unusual stress. Hot or cold showers or baths may relieve a headache. Please make some lifestyle changes if you have chronic tension headaches. This includes getting plenty of sleep and regular stretching exercises for the neck and back muscles frequently, and possibly changing the job or recreational habits. Hope this helps you to relieve the symptoms along with the medications for symptomatic relief. Take care and regards!