Losing a loved one is never easy, but for older adults, it takes a physical toll. (Greg Lehman/Walla Walla Union-Bulletin via AP)

In a follow-up on previous research, University of Birmingham immunologists claim that you really can be sick with grief. This emotionally-driven sickness gets worse the older you are, the researchers reported in a recent Immunity & Aging study, and is probably caused by an increase in stress hormones.

Both young and old study subjects who'd experienced the loss of a loved one recently reported symptoms of stress and depression, showing higher marks than their non-grieving counterparts. But though the young subjects (of an average age of 32) showed no changes in their immune systems, older grievers (average age 72) had weakened immune functions.

During the weeks after an emotional loss, the researchers report, people can suffer from a reduced number of white blood cells called neutrophils, which are needed to fight infection. They now believe that this loss may be related to a fluctuation in stress hormones, which may be more pronounced in older individuals.

"The effects of loss are poorly understood on the whole – we know that it affects the immune system among other things – but we don't fully understand the role played by our stress hormones," lead author Anna Phillips, a professor of Behavioral Medicine at the University of Birmingham, said in a statement. "We hope that this is a step towards that understanding, and being able to provide the best possible support."