What is the cause of a headache?

There are many possible causes of headaches, including:

1. Tension headaches: These are the most common type of headache and are usually caused by stress, anxiety, or depression. They can also be caused by poor posture, dehydration, or eyestrain.

2. Migraines: These are intense headaches that can last for hours or even days. They are often accompanied by nausea, vomiting, sensitivity to light and sound, and dizziness.

3. Cluster headaches: These are severe headaches that occur in clusters and can last for weeks or even months. They are more common in men and the cause is unknown.

4. Sinus headaches: These headaches are caused by inflammation of the sinuses, which are the air-filled cavities behind your forehead, cheekbones, and bridge of your nose. They can cause pain and pressure around your eyes, cheeks, and forehead.

5. Eye strain headaches: These headaches are caused by straining the eyes, such as when you spend long periods of time looking at a computer screen or reading in dim light. They can cause pain around the eyes and temples.

6. Medication overuse headaches: These headaches are caused by taking too much medication to treat headaches. When you take headache medication too often, it can actually make your headaches worse.

7. Head injury headaches: These headaches can occur after a head injury, such as a car accident or fall. They can range from mild to severe and can last for days or even weeks.

8. Certain medical conditions: Headaches can also be a symptom of an underlying medical condition, such as high blood pressure, diabetes, or cancer. If you experience sudden, severe headaches that are accompanied by other symptoms, it is important to see a doctor for evaluation.