Mia emailed me after last month's issue. She said she needed to tell someone what was happening because her doctor kept telling her nothing was wrong.

She is 52. High school guidance counselor, married for twenty-four years, two kids in college, three half-marathons under her belt, and no history of heart trouble.

A few months ago she started waking at 3am with her heart hammering against her ribs. Not fluttering, hammering.

She would lie in the dark counting the beats, sometimes for an hour, wondering if this was the one. Her husband drove her to urgent care twice before she stopped going.

The bloodwork came back fine. The EKG came back fine, and the doctor told her it was probably stress and handed her a pamphlet on anxiety.

Know that feeling? When something is clearly happening in your body, the numbers say you are fine, and you start to wonder if you are the one making it up?

Here is what is happening in Mia, and probably in a lot of the women reading this. Estrogen has been quietly regulating her autonomic nervous system for three decades.

That is the system that runs your heart rate, your breathing, and your blood pressure without you having to think about it. Estrogen helps keep the sympathetic branch, the one that speeds things up, in a steady conversation with the parasympathetic branch, the one that calms things down.

Think of estrogen as a governor on an engine. It kept Mia's heart rate steady even when her cortisol surged in the pre-dawn hours, which it does in every human body around 3 to 4am.

As estrogen fluctuates in perimenopause, that governor loosens, and the morning cortisol rise hits an engine with no brakes on it. The Study of Women's Health Across the Nation, a long-running research project following midlife women through the menopausal transition, has documented palpitations as one of the most commonly reported and least investigated symptoms of this stage of life.

I am sharing Mia's story because she is not the only one lying awake at 3am wondering what is wrong with her. Perimenopausal palpitations are extremely common and rarely discussed, which is why so many women think they are the exception.

Mia's cardiologist eventually confirmed her heart was structurally healthy. What he did not tell her, because most cardiologists have not been trained to, is that estrogen withdrawal can trigger exactly what she was feeling.

If you have found yourself frozen in the dark with a pounding chest, staring at the ceiling and running through worst-case scenarios, the answer may be that your governor is loosening. Not that you are broken.

Two things helped Mia.

👃 First, slow nasal breathing the moment the palpitations started, four counts in through the nose and six counts out through the nose, for two full minutes.

That longer exhale engages the vagus nerve, which sends a direct signal to the heart to slow down. It is free, it works within a few minutes, and it can be done lying in bed.

📔 Second, she tracked her triggers on paper for two weeks. Alcohol after 6pm, caffeine after noon, and skipped meals all made her 3am wake-ups more intense and more frequent.

If your heart is racing or pounding regularly, please get it looked at properly. Palpitations in midlife are often hormonal, but they can also point to thyroid changes, anemia, atrial fibrillation, or another arrhythmia that deserves real attention, and you deserve more than a pamphlet.

You are not losing your mind. You are navigating a biological transition that your body was not built to make quietly.

You are not alone in this. And we are figuring it out together.