You don't need to know all the muscle names or chemical process by which a migraine occurs to understand the basic concept of migraines.
Migraines are caused by a number of factors and triggered by a plethora of things ranging from smells to food to stress or even blood pressure.
There are a few main principles that are at the core of understanding how the body works.
Muscles don’t push, they only contract, hold, and relax.
No muscle works without affecting other muscles.
Muscles move bones.
When your body is in a state of stress, the muscles contract and hold your body into a forward or flexed position. This position is commonly known as fight or flight. When your body is not in a state of stress, the muscles relax and hold only minor tension when needed to perform everyday actions like standing, sitting, and walking.
In the stressed state, your core muscles will contract. Not all muscles will contract equally on all sides of the body, the muscles will contract based on your dominant side or dominant hand. Not everyone who is right handed will contract in the exact same way, but the pattern will be similar.
As your core muscles contract, you will flex forward. This will shorten the muscles on the front side of your body and stretch muscles on your back just like if you ball up your fist. But unlike a fist, your head will tilt up so you can see, not unlike riding a street-style racing bicycle.
So the muscles attaching at your collarbone are pulling down, and this causes your shoulder blades to rise like a hoop-skirt, and your neck extends in a sharp arc backward pulled by contracting muscles in the back of your neck.
The force of the muscles pulling at the front of your neck and collarbone and the muscles contracting in the back of your neck put pressure on the front and back of your head. This is why these are common places for migraines to be felt. People often refer to this feeling as “the halo”. If the pressure continues, the tissue across the top of the head is pulled taught and this is where the “exploding-head” feeling comes from.
The combination of muscles contracted and holding continuously and then contracting even more when a stressful reaction is triggered can result in a migraine. In people that do not suffer from migraines, the muscles may be contracted but not to excess.
