Headache causes can include TENSION, STRESS, DIN, and eyestrain. TENSION is a state of mental or emotional strain caused by adverse or demanding circumstances. STRESS is a feeling of emotional or physical TENSION resulting from factors that create a demand on physical or mental energy. DIN is a loud, confused noise, especially one that is continuous or repetitive. Eyestrain is a condition in which the eyes become tired from intense use or improper vision correction. All of these can cause headaches, making them important to recognize and address.