Headaches can be caused by a variety of factors, often related to tension in muscles, nerve sensitivity, or underlying health issues. Common causes include stress, lack of sleep, fatigue, hunger, caffeine withdrawal, poor posture, and certain foods or drinks like chocolate, alcohol, and processed foods containing additives like MSG or nitrates. Migraines may be triggered by environmental factors such as bright or flashing lights, strong smells, hormonal changes in women, or specific medications. Other causes can be infections, sinus problems, eye strain, dehydration, or more serious conditions like high blood pressure. If headaches are frequent or severe, keeping a headache diary and consulting a healthcare professional to identify specific triggers and underlying causes is recommended. Serious underlying disorders are rare but should be ruled out by a doctor if headaches persist or worsen.