Why Hot Flushes & Night Sweats Happen

Introduction

Hot flashes and night sweats hit at the worst possible times — during meetings, in the car, or right when you finally fall asleep. And in an Australian summer, the combo can feel like your body has switched from “normal human” to “portable heater with trust issues.”

The important part? It’s not random and it’s not a sign your body is failing. Hot flashes are a biological response — a misfire in the system that controls heat, hormones, and stress. When oestrogen shifts, the brain’s internal thermostat becomes jumpy, reacting to tiny temperature changes as if they’re emergencies.

What you feel on the outside — the sudden heat, the flushing, the heartbeat jump, the sweat, the chill that follows — is your body trying (a bit too enthusiastically) to keep you safe. Once you understand the biology behind it, the whole experience makes a lot more sense… and becomes a lot less frightening.

Let’s break down what’s actually happening inside your body during a hot flash, why night sweats join the party, and how small changes in routine can make the waves more manageable — even when the weather is working against you.

Hormones & Your Internal Thermostat

Your body’s temperature control lives in a small area of the brain called the hypothalamus. Under steady hormone levels, it keeps you in a comfortable range without drawing attention to itself.

During perimenopause and menopause, oestrogen starts to fluctuate. Those shifts make the hypothalamus more sensitive, almost jumpy. A tiny rise in internal heat — the kind you’d normally never notice — can suddenly be read as “too hot, fix this now.”

That misreading is what kicks off the hot flash: blood is pushed toward the skin, sweat glands fire, your heart rate lifts, and then the body often overcorrects and leaves you feeling chilled. The system isn’t broken; it’s recalibrating while your hormones change.

Night Sweats: What’s Happening During Sleep

Night sweats are simply hot flashes that happen while you sleep. The biology is the same — a sudden surge of heat, a fast cooling response, and then the “why am I freezing now?” moment — but sleep adds its own complications.

During the night, your body cycles through different sleep stages. Each stage has slightly different temperature patterns, and the hypothalamus becomes more sensitive when you’re transitioning between them. That sensitivity, combined with changing hormone levels, is why night sweats often feel stronger or more disruptive than daytime flashes.

Bedding, room warmth, alcohol, spicy meals, late-night stress, and even a warm partner can amplify the response. Because you don’t wake up early enough to remove layers or cool down, the whole heat-dumping cycle tends to run longer and feel more dramatic.

When to Check With Your GP

Hot flashes and night sweats are common during perimenopause and menopause, and for most people they’re simply a sign of hormonal transition. But there are times when it’s worth getting things reviewed — especially if the pattern doesn’t match typical hormone-related changes.

A quick check-in can rule out other causes such as thyroid changes, infections, iron issues, medication effects, or anything that mimics vasomotor symptoms. It’s not about assuming the worst — it’s about making sure nothing important is hiding underneath.

Most of the time, reassurance and symptom support are all that’s needed. But if something feels off, checking in keeps you on the safe side and gives you a clearer understanding of what’s going on.

Hot Flash & Night Sweat Checklist

Tick the ones that feel true for you. This isn’t a diagnosis — it’s just a way to notice patterns your body might already be hinting at.

• I feel sudden waves of heat rising through my chest, neck, or face.
  This is the classic vasodilation pattern — your cooling system turning on quickly.
• I often get a cold chill after the heat passes.
  The body sometimes overcorrects after dumping heat, which causes a brief cool-down drop.
• Night-time episodes feel stronger or longer.
  Sleep makes heat harder to regulate — bedding, room warmth, and sleep cycles all add to it.
• Alcohol, caffeine, or spicy foods seem to make things worse.
  These stimulate the nervous system and widen blood vessels, creating stronger heat surges.
• Stress or rushing often triggers a flash.
  Cortisol narrows your thermostat’s comfort zone — making flashes more likely under pressure.
• My room temperature or bedding affects how often it happens.
  Even small environmental heat increases can set off an already-sensitive hypothalamus.

Herbal Support Picks for Hot Flashes & Night Sweats

Sage

Black Cohosh

Chaste Tree

Red Clover

FAQs

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Disclaimer

The information in this article is general and for educational purposes only. It is not a substitute for personalised medical advice, diagnosis or treatment. Hot flashes and night sweats can have many causes, and the right approach depends on your individual health history.

Please speak with your GP or a qualified healthcare professional before starting new supplements, changing medications, or making significant adjustments to your health routine. This is especially important if you are pregnant, breastfeeding, have a hormone-sensitive condition, have a chronic illness, or are taking prescription medication.

Always read the label and follow the directions for use. If your symptoms are severe, sudden, persistent, or accompanied by fever, weight loss, chest pain or anything that feels unusual, seek medical attention promptly. For our full Health Disclaimer & Liability Notice, visit this page.