A secondary headache is a type of headache that is a symptom of another underlying medical condition or disease. Unlike primary headaches, which are not associated with any underlying cause, secondary headaches are a result of an identifiable and usually serious underlying problem. There are numerous potential causes of secondary headaches, including: Head Injury: Traumatic head injuries can lead to headaches as a symptom. Sinusitis: Inflammation of the sinuses can cause pain and pressure in the head. Migraines: While migraines can be primary headaches, they can also be secondary if they are triggered by an underlying condition. Medication Overuse: Excessive use of pain medications, especially those containing caffeine or codeine, can lead to rebound headaches. Infection: Various infections, such as meningitis, encephalitis, or a sinus infection, can cause secondary headaches. High Blood Pressure: Hypertension (high blood pressure) can lead to headaches, especially if it is seve...