Veterans who suffered physical injuries or developed post-traumatic stress disorder after combat in Iraq or Afghanistan may suffer recurrent headaches, a new study suggests.

In surveys of 308 veterans, researchers found that those who had suffered combat injuries were at greater risk of developing migraine headaches. Meanwhile, those who screened positive for post-traumatic stress disorder (PTSD) had elevated rates of both migraine and tension-type headaches.

The findings, say the researchers, suggest that veterans with either physical injuries or PTSD should also be asked about chronic headaches.

Dr. Niloofar Afari and colleagues at the University of California, San Diego and the Veterans Affairs San Diego Healthcare System report the findings in the journal Headache.

A few past studies have suggested that PTSD may be associated with higher headache risks. But because PTSD often arises after a physical injury, it has not been clear whether the stress disorder itself is linked to headache risk.

In the new study, physical injury and PTSD were each independently associated with higher headache risks.

Of the veterans Afari’s team assessed, 40 percent screened positive for PTSD, while 17.5 percent had combat-related physical injuries only. When it came to headache, 10 percent said they had been diagnosed with migraine, 10 percent reported a diagnosis of tension- type headache and 6 percent said they had been diagnosed with both.

Overall, vets with physical injuries only had more than twice the risk of recurrent headaches as those without such injuries. The risk was four times higher among veterans with PTSD versus those without the disorder.

When the researchers looked at headache type, they found that physical injuries were related to migraines only, while PTSD was linked to migraines and tension headaches.

PTSD could raise headache risk for a number of reasons, according to the researchers.

There is some evidence, for example, that psychological stress can help trigger headaches via the body’s physiological responses to stress, including chronic activation of parts of the nervous and hormonal systems. It’s also possible that some people have underlying vulnerability to both PTSD and chronic headaches.

Whatever the reasons, the researchers write, “our findings underscore the need to assess for PTSD and headache co-occurrence and to provide adequate treatment for the symptoms of both.”

As for physical injuries, the researchers found that general injuries, but not Head injury specifically, were related to higher migraine risk.

That finding, Afari’s team writes, is in line with those from another recent study - suggesting that combat-related physical injury in general is a risk factor for headaches in veterans.

More studies are needed to confirm the current findings and understand the potential reasons for them, the researchers say. But the implication, they write, is that veterans could benefit from comprehensive assessments of their physical, mental and emotional health.

SOURCE: Headache, October 2009.