Because you suffer from migraines, getting a bad headache is not new to you. If your migraine pattern changes or your headaches suddenly feel different, it could be a sign of a more serious medical condition.
Call your doctor right away if you experience any of the following:
A severe headache that comes out of the blue, sometimes described as a "thunderclap." Migraine headaches can be severe at times, but if you have a headache that comes on suddenly in a different way than your usual migraines and feels like the "worst of your life," it is worth a call to your doctor.
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A headache associated with seizures
A headache after a recent sore throat or respiratory illness. During cold and flu season, when sore throats are common, migraines sometimes become more frequent. The warning sign of something more serious is usually when the sore throat goes away, but then fever, stiff neck, or really severe headaches, which are unusual for you, develop.
A headache that follows a head injury, especially if it it keeps worsening in intensity
A chronic headache that is triggered by exertion or gets worse if you cough, exert yourself, or move suddenly
Unfamiliar headache pain after age 50
Headache pain that requires daily use of medications, which your doctor did not prescribe as preventative (also called "prophylactic") medication