The second he said adios, your adrenal glands started churning out the hormones cortisol and adrenaline, the costars of the body's fight-or-flight stress response. Depending on how bad the breakup was, your stress hormones are anywhere from simmering to skyrocketing (a reaction that, like all of the below, can settle down after a few days or last for years)--and they're likely ratcheting up your blood pressure.
It's like clockwork: Your eyes hit that photo of the two of you and--boom!--awful stomach pit. You feel sick, yet you can't look away. That's because the moment you saw his face, blood started rushing to your brain's pleasure center, the ventral tegmental area. These are all the good times talking.
The command center for craving and longing also lights up. It demands attention--one reason you're obsessed with driving by your ex's house, stalking his Facebook page, or trying to replace him with some other satisfier (welcome, merlot and Ben & Jerry).
But rejection also sends blood flow to two other areas: the secondary somatosensory cortex and the dorsal posterior insula, both involved in producing physical pain. That's why you may feel achy all over, not just in your heart.
Initially crowded out by the above responses, your left prefrontal cortex slowly starts to light up. This part of your brain is responsible for reassessment and evaluation--the one saying, Maybe it's for the best. A mere whisper now, this signal will get stronger as time goes on.
Your stressed-out nervous system signals your digestion to slow way down. Your stomach hurts, and you have zero appetite--except maybe for that pint of ice cream.
The stress of rejection might agitate your body's immune system, leading to cell-damaging inflammation. The parts of your immune system that fight infection and keep viruses under control start to lose steam. You may get sick or develop a cold sore (yeah, great, just what you need right now).
That free-flowing cortisol? It's triggering a pore-clogging oil buildup underneath your skin. Hence, why a broken heart is often accompanied by acne.
If you're totally devastated, some of the hair follicles on your head could enter a state called telogen effluvium. That's medspeak for "resting phase," in which your strands stop growing or, after a while, start falling out.
Don't worry--that reassessment area of your brain is no JV player. Soon enough, it will have you thinking, Yes, it was for the best. You'll grow new hair--and find new love.
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