When a headache, vomiting, fever, or a seizure occurs along with another serious illness, immediate medical care is needed. Signs of serious illness include:

• A sudden, severe headache.
• Confusion or extreme irritability.
• Extreme sleepiness.
• New and different skin rash or severe bruises that appear without an injury.
• New double vision, blurred vision, or blind spots.
• Persistent nausea or vomiting.
• Rapid, difficult breathing.
• Severe neck stiffness or pain.
• Severe sensitivity to light (photophobia).
• Severe pain.
• Unsteadiness that prevents standing or walking (ataxia or vertigo).

Although uncommon, a headache with signs of a serious illness may be a sign of:

• An infection in or around the brain, such as encephalitis, meningitis, or a brain abscess.
• A momentary blockage of a blood vessel (transient ischemic attack, or TIA) in the brain.
• Rupture of a blood vessel in the brain.

Call your doctor for an evaluation if you have a headache and other signs of a serious illness.