What is migrain?? what causes it?

What is migrain? what causes it?
A headache of varying intensity, often accompanied by nausea and sensitivity to light and sound.
Migraine headaches are sometimes preceded by warning symptoms. Triggers include hormonal changes, certain foods and drinks, stress, and exercise.

Symptoms: Usually self-diagnosable
Migraine headaches can cause throbbing in one particular area that can vary in intensity. Nausea and sensitivity to light and sound are also common symptoms.

People may experience:
Pain areas: in the face or neck
Pain types: can be dull
Headache: can be acute, frequent, or throbbing
Visual: sensitivity to light, distorted vision, or seeing flashes of light
Whole body: dizziness, lightheadedness, or malaise
Sensory: aura or sensitivity to sound
Gastrointestinal: nausea or vomiting
Also common: irritability, nasal congestion, or scalp tenderness.

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What is the example? i’ll be happy to answer if you can tell me : )

To wear the full equipment.