Skip meals or go too long without eating
Dehydrate yourself by not drinking enough water
Sleep too little or sleep at irregular times
Stare at bright screens for long periods without breaks
Spend time in loud environments
Tense your neck, jaw, or shoulders for extended periods
Stay in a poorly ventilated room
Consume too much caffeine or suddenly stop caffeine
Expose yourself to strong odors like perfume or smoke
Ignore stress and let it build up
Read or work in dim lighting
Hold your head in one position for too long
Drink alcohol
Eat foods that personally trigger headaches
Avoid taking breaks during long periods of concentration