Attack on Titan: Why does Mikasa get headaches? The Eren connection explained

Mikasa getting a headache (Funimation)
Mikasa getting a headache (Funimation)

Attack on Titan is one heck of a wild ride. It has many characters and plot threads, from the Titans and their origins, to the world outside of the walls and characters with their own individual arcs.

One of the most consistent plot threads, however, is Attack on Titan's Mikasa Ackerman's many headaches. Mikasa is a long-time friend of series protagonist Eren Yeager and a bonafide Titan killing machine, but from time to time, she seems to suffer a headache that goes unexplained.

Attack on Titan: Mikasa's headaches, explained

As many readers are well aware, Attack on Titan series author Hajime Isayama likes to create an intricate web of plot threads that always see some kind of resolution or payoff at the end. But one of the most confounding is Mikasa's recurring headaches.

At the end of the series, Eren reveals some pretty shocking twists and turns about Mikasa and her bloodline. He stated:

"The Ackermans were created as tools to serve the royal family. When you awakened your powers, the Mikasa of that day died."

In this, Mikasa's headaches were the result of Eren telling her to "fight" when they were younger.

In addition, it does explain her radical devotion to Eren, even to the point of attacking Armin to keep him safe. Even with tears in her eyes, Mikasa couldn't believe that was the truth. In Eren's eyes, the Mikasa he knew died a long time ago, and the person standing before him was the Ackerman's tool.

Basically, the headaches were Mikasa's younger, original self, conflicting with her new 'programming.' A cruel fate if there ever was one, even in Attack on Titan.

That explanation only fell short when Eren himself admitted that he was just making it up, and the order to "fight" came way before he became a Titan Shifter himself. In addition, Levi nor Keen show any signs of such devotion. Mikasa's family tree also lends credence to the idea that Eren was, in fact, lying. Or, failing that, using incomplete information and drawing an incorrect conclusion.

The Ackerman family was once part of Eldia, the island on which most of the series takes place, and were the accidental result of various Titan experiments.

Rather than turning into an Attack Titan like Eren, Annie, and other shifters do, the Ackerman clan has otherwise taken on the power of a Titan while remaining in human form. This trait was passed on through Ackerman's bloodline, and helps explain why series favorites like Levi Ackerman can pull off the insane stunts he can do.

It also resulted in immunity to the Founding Titan, further disproving Eren's theory. Eren admitted to Armin in "The Path" that most of what he said was false and was trying to rile them up.

So what's the truth?

There are many theories and questions floating around the internet. Many Attack on Titan fans believe that her headaches are the result of trauma. Simple migraines are brought on by pre-existing conditions that surface whenever a scenario erupts or if she meets a traumatic scene that reminds her of that grisly night.

Another theory is that her headaches are Ymir, the original one, trying to control Mikasa, and the pain is the result of her immunity clashing against the attempted commands. For that, this explanation seems the most likely.

However, there is one point of fact that still needs to be explained. According to a page in chapter 139, Mikasa stated that her headaches were Ymir attempting to look into her head. Rather than an attempt at control, it was likely that Ymir was just trying to see through Mikasa's eyes.