Hot Flushes and Night Sweats in Menopause: Why They Happen and How Long They Can Last

Hot flushes and night sweats are among the most common symptoms of menopause. Although most women associate them with the period after their final menstrual period, they can appear already during perimenopause. Vasomotor symptoms are estimated to affect around 75% of women after menopause, and nearly a third describe them as severe.

What does a hot flush feel like?

A hot flush is a brief episode of an intense sensation of heat, most often felt in:

• the face
• the neck
• the upper chest
• the arms

It is often accompanied by:

• flushing of the skin
• noticeable sweating
• a pounding heart
• a sense of anxiety or unease

Once the flush subsides, a feeling of cold or shivering may follow. When flushes happen at night, they can significantly disrupt sleep quality and contribute to daytime fatigue.

How long do hot flushes last?

For a long time it was believed that hot flushes lasted only a few years. Today we know that the reality is often different. The median duration of vasomotor symptoms is roughly 7 years. Even among women aged 60–65, around 42% still experience hot flushes or night sweats, and about 6.5% rate them as moderate to severe.

Individual experiences, however, vary widely. Some women have symptoms for only a few months, while others live with them for many years.

Why do hot flushes happen?

The precise mechanism behind hot flushes is still not fully understood. The most likely explanation is a change in how the thermoregulatory centre in the hypothalamus works — the part of the brain that controls body temperature.

During perimenopause, the so-called thermoneutral zone narrows. The body then becomes much more sensitive even to small changes in body temperature. This means that a small rise in temperature can trigger sweating, and a small drop can cause shivering or a feeling of cold.

Is it only about falling estrogen?

Low estrogen plays a key role, but it is not the only factor. Not every woman with low estrogen has hot flushes, and their intensity varies markedly between women. This suggests that other mechanisms also contribute, including:

• the central nervous system
• serotonin
• noradrenaline
• the brain’s individual sensitivity to hormonal change

That is why two women with the same hormonal values can have a completely different experience.

Worth remembering

Hot flushes are not only about feeling hot. They are a complex neuroendocrine symptom arising from changes in body temperature regulation and hormonal shifts during the menopausal transition. Although they are very common, both their duration and intensity are highly individual.

If they significantly affect quality of life, sleep or day-to-day functioning, effective treatment options exist — including hormone therapy or holistic approaches such as CBT (cognitive behavioural therapy).