Summary

•  Hot flushes are a common symptom of menopause.
• 75-80% of women will have hot flushes.
• The frequency and intensity vary.
•  The exact causative mechanism is not known.
  

What are hot flushes?

Experiencing hot flushes (also called flashes) is the feature that has made the menopause famous because it’s the most common symptom. 75-80% of women suffer these feelings of intense heat over the trunk and face with an accompanying flushing of the skin.

A hot flush generally lasts less than five minutes, and the sweating that accompanies this “attack” usually starts a minute after the feeling of palpitations.

A hot flush may be followed by a chill and some women may become aware that their heart is beating fast or hard and they may feel anxious.

How often and when do they occur?

The frequency of flushing may range from one or two per day to one every 15-30 minutes. Flushing is more pronounced late in the day, in hot weather, after ingestion of hot foods or drinks, or during periods of stress and tension. If thoughts about the general troubles of life don’t keep you awake at night, these symptoms will, and they may lead to fatigue and depression. Hot flushes at night are called night sweats.

Hot flushes can begin during perimenopause before menstruation stops. Most women have hot flushes for more than a year while 25-50% will suffer for up to five years if they’re not treated.

What causes hot flushes?

Hot flushes are believed to be due to a change in oestrogen levels, which influences the hypothalamus (steering centre in the central nervous system) in its control (via the hormome Gn-RH released by the hypothalamus) of the temperature-regulating area in the midbrain.  

The severity and frequency of hot flushes are directly correlated with the reduction of oestrogen levels over time. A premenopausal woman whose oestrogen level suddenly drops (for example after her ovaries have been surgically removed) is more likely to experience hot flushes compared with a woman who experiences a gradual decrease in oestrogen while entering her climacteric time frame.

Home treatment of hot flushes

Here are some tips that could be helpful:

• Keep your home and workplace cool.
• Wear loose clothing in layers that are easily removed.
• Drink plenty of water and juice. Avoid caffeine, alcohol and spicy foods if they bring on hot flushes.
• Exercise regularly to help stabilise hormones and prevent insomnia. Although hot flushes can occur during exercise, regular exercise can help beat flushes and relieve insomnia.
• Avoid confined spaces and hot, humid weather.
• Drug treatment: about one in four women suffer from such severe hot flushes that they need hormone therapy (HT). HT is the most effective treatment for menopausal symptoms. See the section on treatment for information on hormone therapy.

Night sweats

Hot flushes at night are called night sweats.

What you can do

• Wear light pyjamas.
• Have a brief shower if you wake up drenched.
• Wear wet pyjamas.

Drug treatment

Hormone therapy may be the only effective treatment to alleviate severe symptoms. 

Reviewed and updated by Dr Alan Alperstein, obestetrician and gynaecologists in Cape Town, in February 2011. 
Previously partly reviewed by Dr Mike Davey, President of the South African Menopause Society & Dr Tobie de Villiers, gynaecologist and committee member of both the South African Menopause and International Menopause Societies.