Scans carried out by University of California, Los Angeles (UCLA) scientists showed that the part of the brain that deals with physical pain, the anterior cingulate cortex, processes emotional pain, too.

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This is commonly known as "broken heart syndrome", also termed stress or takotsubo cardiomyopathy. It usually follows "significant emotional or physical stress", according to the British Heart Foundation. The heart muscle suddenly becomes weakened and one of the heart's chambers changes shape.

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The Great loss of someone close can leave people more vulnerable to infection. A University of Birmingham study found that, especially among the elderly, those who are recently bereaved can suffer from reduced function of neutrophils - the most abundant type of white blood cell, which fight off rapidly dividing bacteria like pneumonia.
http://www.bbc.co.uk/news/magazine-36213249