Lou Ferrigno is looking a little green.

“The Incredible Hulk” star revealed on Instagram he was hospitalized this week after he went to get a pneumonia shot – presumably a vaccine – and ended up with fluid in his bicep. He posted an unhappy looking snap in a green hospital gown, warning his 87,000 Instagram followers about his condition.

“Went in for a pneumonia shot and landed up here with fluid in my bicep,” he wrote Thursday. “I’ll be ok but it’s important that you keep an eye on who’s giving the shot and make sure they not only swab the spot correctly but that you watch the needle come out of the package.”

The 67-year-old actor’s fans crowded his Instagram comments field with well wishes, sending him their concerns.

One fan wrote, “Lou! Please get better very soon. You're such an inspiration to me and for so many!”

On Friday, Ferrigno revealed he was doing better. On Thursday night after he was released from the hospital, he attended a Smash Global MMA event in Los Angeles.

“What a great night with @smashglobal and @steveorosco,” he wrote. “Really great getting to hang out with some old friends as well @dolphlundgren. Happy I made it out of the hospital in time.”