Why do i get migraines?

Migraine is a type of headache that can cause very strong pain, usually on one side of the head. It can also make you feel sick or sensitive to light and sound. Migraine happens because of a problem in the brain that affects the nerves and blood vessels. What happens in your body when you have a migraine? Something like stress, lack of sleep, certain foods, or changes in the weather, triggers your brain to start a migraine. Then your brain sends signals to a group of nerves called the trigeminal nerves. These nerves are connected to the blood vessels on the surface of your brain and in your face, eyes, teeth, and forehead. The trigeminal nerves release chemicals that cause the blood vessels to expand or dilate. This increases the blood flow to your brain. This also causes inflammation and swelling in the outer layer of your brain, called the meninges. After that, a wave of activity travels across the surface of your brain, called a spreading cortical depression. This wave makes some parts of your brain less active and reduces the oxygen supply. This may cause you to see or feel strange things like flashes of light, blind spots, tingling, or numbness. This is called an aura.

Finally, the increased blood flow, inflammation, and reduced oxygen cause pain in your head. The pain can be throbbing or pulsing and can get worse with movement or noise. This is the headache phase of the migraine.

References What Happens to the Body During a Migraine Attack?. How a Migraine Happens | Johns Hopkins Medicine.