JACKSONVILLE, ONSLOW COUNTY -

For some military members, fireworks may spark memories of the times they spent in combat.

Corp. Stephen Jackson, 23, has been deployed to Afghanistan twice.

Jackson started his two weeks of leave on July 1 and wanted to buy some fireworks to take home during his visit to Ohio.

He has no problem lighting off fireworks. But when fireworks go off without warning, he would start to feel the effects from his time in combat.

"It catches you off guard, you kind of flinch from it,” said Jackson.

A Naval hospital doctor said it’s not unusual for veterans to have a reaction like Jackson’s when fireworks are going off.

"There is a potential for these patients to have a heightened awareness and / or a reaction to the fireworks," said Dr. David Barrows of Naval Hospital Camp Lejeune.

Jackson is usually able to deal with his memories of his time in Afghanistan. But he said he's had experiences that remind him of his time in combat.

"There's actually been a couple times where I've heard a really loud bang driving along and I thought it was a gunshot. I kind of had a flashback and I like froze,” said Jackson.

Dr. Barrows said fireworks can affect veterans differently. Some veterans may have a genetic predisposition that determines their susceptibility to Posttraumatic Stress Disorder.

"Some people may be more resilient from a genetic stand point for PTSD," said Barrows.