Hot Flashes

A hot flash is a sudden wave of heat through the face, neck and chest. It often comes with flushing, sweating and a fast heartbeat, and it can last from a few seconds to several minutes. When the same thing happens at night and wakes you, it is called a night sweat.

What hot flashes are, and what they are not

Hot flashes and night sweats are grouped together as vasomotor symptoms. As hormone levels shift around menopause, the part of the brain that controls body temperature becomes more sensitive, so the body reacts as though it is overheating. The heat is a real physical response, not something you are imagining.

They are also not a short phase for everyone. The World Health Organization notes that how common menopause symptoms are, and how long they last, varies a great deal between individuals. Some people have vasomotor symptoms for a few months and others for years. In a national survey of Canadian women aged 40 to 60, hot flashes were the most commonly reported menopause symptom of all, and almost everyone surveyed reported at least one menopause symptom.

Signs and symptoms

• A sudden wave of heat in the face, neck and chest
• Flushing or redness of the skin
• Sweating, sometimes heavy, followed by chills
• Night sweats that wake you from sleep
• A racing or pounding heartbeat during an episode
• Broken sleep and daytime tiredness
• Irritability or trouble concentrating around episodes

How often episodes come, and how strong they feel, differs widely from person to person, and can change over months and years in the same person.

What raises the risk

Some things cannot be changed:

• Being in the menopause transition, which for most people happens between ages 45 and 55
• Early menopause, or menopause that follows surgery to remove the ovaries
• Menopause brought on by cancer treatment such as chemotherapy or endocrine therapy
• Family history, and individual differences in how the body responds to hormone change

Others can often be worked on, usually with support from a health care team:

• Smoking
• Higher body weight and low physical activity
• Everyday triggers some people notice, such as alcohol, caffeine, spicy food, warm rooms and stress

How hot flashes are diagnosed in Canada

There is no blood test that confirms hot flashes. A family doctor, nurse practitioner or gynaecologist makes the assessment from your age, your menstrual pattern and how you describe your symptoms, often supported by a symptom diary kept over a few weeks. Blood tests may be ordered to look for other explanations such as thyroid conditions, or to help assess menopause in people younger than 45. Because there is no single test, a clear account of when episodes happen, how long they last and what they interrupt is the most useful thing you can bring to the appointment.

Treatment and day-to-day management

Clinical research for Hot Flashes is enrolling. See the current studies ↓

Care in Canada is aimed at easing symptoms and protecting sleep, work and daily life. What is appropriate depends on your symptoms, your medical history and what matters to you. A health care team may discuss:

• Menopausal hormone therapy, available here as tablets and as patches and gels, with a progestogen added for people who have a uterus
• Non-hormonal prescription medicines for vasomotor symptoms, including neurokinin receptor antagonists authorised by Health Canada and an alpha-2 agonist, as listed by the BC Provincial Academic Detailing Service
• Local vaginal hormone products, and a vaginal steroid precursor, for genitourinary symptoms of menopause
• A selective estrogen receptor modulator taken by mouth for painful intercourse related to menopause
• Referral to a specialised menopause service, such as the Complex Menopause Clinic at BC Women\’s Hospital and Health Centre

What suits one person will not suit another. Which of these applies to you, if any, is a decision for you and your own clinician, and this page is not a recommendation about any of them.

When to talk to a doctor

• Book an appointment if hot flashes, night sweats or broken sleep are affecting your work, mood, relationships or daily activities, or if you simply want to understand your options.
• Speak to a clinician if menopause symptoms begin before age 45, or if your periods stop before age 40, because this is assessed differently.
• Seek prompt medical attention for vaginal bleeding after menopause, or for chest pain, fainting or shortness of breath happening with episodes, since these need separate assessment.

Why clinical research matters for hot flashes

It is still not understood why some people have vasomotor symptoms for a few months while others have them for a decade or more, or why patterns differ across populations and for people who reach menopause early or after cancer treatment. Canada also has no national count of how many people have moderate to severe symptoms, or how many receive any care: the Canadian figures on this page come from national surveys by the Menopause Foundation of Canada rather than from health surveillance. Studies now recruiting are examining neurokinin receptor antagonists and other non-hormonal compounds, different hormone doses and delivery routes, and behavioural, sleep and digital health approaches.

Clinical studies are how those questions get answered. Taking part is voluntary, you give informed consent before anything begins, and you can stop at any time without affecting the care you get from your own doctor. Joining a study does not mean giving up your current treatment, and no one can tell in advance whether a study will help you personally.

Learn more from Canadian sources

• Menopause Foundation of Canada
• Menopause and U, Society of Obstetricians and Gynaecologists of Canada
• SOGC statement on the use of menopausal hormone therapy
• BC Provincial Academic Detailing Service: medicines for menopause symptoms