Why did Goku get the heart virus?

[cesarcoronel07]

Just why? I never quite got why he got it

[Hellspawn28]

He most likely catch it like any other virus and got sick like any other normal human on Earth.

[Tyro]

He most likely caught it sometime on Earth because the human population is also contagious to it in the same way (heart). It was also likely to be a new disease since they didn't have a medicine for it yet.

[Big Momma]

My personal belief is that he got it from the Yadrats.

[El Diabeetus]

Toriyama probably wanted to give Trunks a semi-legitimate rwason for being rather than 'Lol, future kid here. Androids are gonna kill all of you.'

[Hellspawn28]

My personal belief is that he got it from the Yadrats.

That's what most fans believe. There's never real proof that he got from Yadrat.

[penguintruth]

Pocket bacon.

[Fizzer]

I think he caught something fairly normal but his Saiyan body caused some kind of mutation, creating a super virus. I also believe he'd be able to fought off any normal virus from Earth. Goku was the first case, but it became widespread and killed a lot of people, which is why there was a cure in the future. However, in the altered timeline that didn't happen, which led to some pretty enormous indirect changes in the world, such as the cyborgs being different. Perhaps in the original timeline Gero had to abandon his plan to transform himself into a cyborg and release 17 and 18 early because he had the virus. I think the virus is somehow responsible for the differences anyway.

[Cold Skin]

We can also wonder about the factor that made it late on the regular timeline.
Maybe he didn't get to go where he caught it until a later time, due to his daily life having been changed from "doing nothing" to "intensive training with Piccolo and Gohan everyday".
Maybe he caught it at the same place/time, but it's the developement of the virus that took more time due to Goku training daily and strengthening his body. Although the Super Saiyan state is said to accelerate the virus' actions once it's active, it may have no impact or even a positive impact when the virus is still sleeping.

All that we know is those two events changed due to Trunks' revelations and may therefore be linked somehow:
- Goku's daily life was changed from "nothing in particular" to "daily intensive training as a Super Saiyan" (changing a lot of factors, like availability to go shopping, places he went to, activity of his body...).
- The virus showed effects much later than expected.

[rereboy]

I think he caught something fairly normal but his Saiyan body caused some kind of mutation, creating a super virus. I also believe he'd be able to fought off any normal virus from Earth. Goku was the first case, but it became widespread and killed a lot of people, which is why there was a cure in the future. However, in the altered timeline that didn't happen, which led to some pretty enormous indirect changes in the world, such as the cyborgs being different. Perhaps in the original timeline Gero had to abandon his plan to transform himself into a cyborg and release 17 and 18 early because he had the virus. I think the virus is somehow responsible for the differences anyway.

Not one of Goku's friends and family died because of his virus in the future (when they had no cure). So, it can't be that contagious.

I think its a earth decease, a very serious, but one that isn't very contagious. It probably has existed for years, but the scientists researching it didn't come up with a cure before Goku died. Actually, they probably came up with the cure not long before Goku died, because I don't see them being able to do that with most of their world already destroyed by the androids. Unless it was Bulma who discovered the cure, but Trunks didn't mention that so it probably wasn't her.

[Marco Polo]

He most likely caught it sometime on Earth because the human population is also contagious to it in the same way (heart). It was also likely to be a new disease since they didn't have a medicine for it yet.

What makes you think that the human population would not be contagious to it if Goku had not caught it on Earth?

[Tyro]

I'm saying the most likely case is that Goku got the virus sometime on Earth, probably while training to fight the cyborgs. Enough of the Earthling population seem to be susceptible to the virus in the same way (heart), and it is/becomes a problem worth making a specific medicine for. It's less likely that Goku spread some epidemic across the planet or an alien disease somehow made its way to Earth.

[DoomieDoomie911]

I'm sure he caught it just as a human catches the flu.

[the_abberration]

Possibly, Goku contracted the virus from Ginyu, or rather the pod he was using. He was probably using the life support/breathing apparatus for those trips (Namek-Yardrat-Earth). Although the air was breathable for Goku, there may have microbes that while not harmful to Ginyu, resulted in the heart virus for Goku.