Why heartbreak hurts in your chest

Three weeks after Ruby's relationship ended, she went to the GP.

She wasn't there about the breakup. She was there because there was a weight in the middle of her chest that hadn't lifted in days, because she'd stopped being able to eat properly, because she kept waking at 4am with her heart going. Something felt physically wrong, and she was half-convinced it was.

The doctor listened, checked her over, asked a few questions, and then asked the one Ruby hadn't expected. "Has anything happened recently?"

She started crying in the chair, and then apologised for crying, and then said the thing she'd been telling herself for three weeks: "It's just a breakup. I'm being dramatic."

She wasn't. And the science on this is a lot clearer than most people realise.

In 2003 a team of psychologists at UCLA, led by Naomi Eisenberger, put people in a brain scanner and had them play a simple ball-tossing game with what they thought were two other players. Partway through, the other players stopped throwing them the ball. That's it. A minor social snub from strangers in a computer game. And yet the scans showed activity in the dorsal anterior cingulate cortex, a region that lights up when you're in physical pain. The paper, published in Science, was titled "Does Rejection Hurt?", and the answer was yes, in the same part of the brain that registers a burn.

Eight years later Ethan Kross and colleagues went further. They recruited people who'd been through an unwanted breakup in the last six months, showed them a photo of their ex, and asked them to think about the rejection. Then, separately, they applied real heat to their arm, hot enough to hurt. The two experiences overlapped not just in the emotional regions but in the sensory ones, the parts that actually process the feeling of pain in the body. Their paper, in PNAS, argued that social rejection and physical pain share a neural pathway more than anyone had thought.

There's an even stranger study that makes the point. In 2010 Nathan DeWall's team gave people either a common over-the-counter painkiller or a placebo every day for three weeks and had them log their hurt feelings. The painkiller group reported less social pain. Please don't take that as advice, it isn't, but as evidence it's remarkable. A drug for headaches took the edge off rejection.

Florence Williams, a science writer, went through a brutal divorce and spent two years reporting on exactly this, and her book Heartbreak is the best account I've read of what the body does after love ends. Stress hormones stay elevated. Sleep breaks. Immune function dips. Appetite goes. She interviews researchers who describe heartbreak, without exaggeration, as a health event. Ruby's GP wasn't humouring her. Ruby's GP was right to ask.

So what changes if you take this seriously?

For one, you stop apologising for it. You wouldn't apologise for limping on a sprained ankle. You'd rest it, you'd tell people, you'd give it time. Heartbreak deserves the same status. Cancel the thing you don't have the energy for. Tell your manager you're going through something. Let people bring you food.

For another, you treat the body, not just the story. Sleep is the first thing to protect, because everything gets worse without it. Eat, even if it's toast. Walk, because Williams found that movement outdoors was one of the few things that reliably brought her nervous system down. Talking helps, but so does the boring physical stuff, and the physical stuff is often easier to start.

Ruby's doctor didn't give her anything. She gave her a name for it, which turned out to be enough to stop the 4am panic that something was wrong. Something was. It was healing.

If it hurts in your body, that's because it happened to your body. Treat it like the injury it is.