Hot flushes and sweats in women
Cancer or cancer treatment can lower the levels of sex hormones in the body. This can lead to hot flushes and sweats.
The main female sex hormones are oestrogen and progesterone.
Hot flushes are one of the most common symptoms women have when they go through the menopause. But hot flushes can also happen because of treatment for cancer.
Women having a natural menopause may find their hot flushes start before the menopause. They usually become less frequent and less severe during the 5 years after their last period. But for many, the hot flushes can go on longer.
Hormone therapy to treat breast cancer
Most women have hot flushes after hormone therapy for breast cancer treatment. This is because the treatment lowers or stops sex hormone production.
Chemotherapy and hot flushes
If you are close to the age that you would naturally start the menopause when you have chemotherapy, you are more likely to go into the menopause. This means you are also more likely to have symptoms, such as hot flushes during your treatment.
How hot flushes may feel
Hot flushes can vary from one person to another. They can start as a feeling of warmth in your neck or face. This often spreads to other parts of your body. You might have:
- reddening of the skin
- light or heavier sweating
- feelings of your heart beating in your chest (palpitations)
- feelings of panic or irritability
Hot flushes can last between 2 to 30 minutes but can be longer for some. How often you have them varies from person to person. You might have more than one a day, and for others, it can be less frequent. And they can continue for many months or years.
They can also make sleeping difficult, which can make you feel tired or anxious.
Causes of hot flushes
It's not clear exactly how hormonal changes cause hot flushes. One idea is that the part of the brain called the hypothalamus controls the production of many hormones. It also controls our body temperature. It may be when oestrogen levels are low the hypothalamus can’t control body temperature as well as it should. And this could cause hot flushes.
We need more research to find exactly what causes flushes. So doctors can develop treatments that work better at controlling them.
Tips to help with hot flushes
Some of the following tips might help to reduce the frequency or intensity of flushes.
- Keep your room cool – use a fan if necessary.
- Wear layers of light clothing so you can easily take clothes off if you overheat.
- Have layers of bedclothes to remove as you need to.
- Wear natural fibres such as silk or cotton instead of synthetic (artificial) fabrics.
- Spray your face with a cool water atomiser.
- Have a lukewarm shower or bath instead of a hot one.
- Put a towel on your bed so you can easily change it if you sweat a lot at night.
- Cooling pads or pillows can help to keep you cool.
- Try to stay calm under pressure as heightened emotions can cause a hot flush to start.
- Sip cold or iced drinks.
- Cut out or reduce alcohol and caffeine drinks such as tea and coffee.
- Reduce or stop smoking (nicotine).
- Cut out or reduce the spicy foods you eat.
Hot flushes usually start to improve over time.
Treatment for hot flushes
If you are finding it difficult to manage your hot flushes, do talk to your doctor or specialist nurse. There are medicines that may help, but not all treatments are suitable for everyone.
Keeping a diary
Hot flushes are often triggered by certain foods or drinks. Some people find that keeping a diary of their hot flushes can help them manage this problem. You can show the diary to your doctor or specialist nurse.
Drug treatment for hot flushes
Anti depressants
Research has shown that certain antidepressant medicines can be helpful in treating hot flushes. They can reduce the number and severity of hot flushes.
But doctors don’t recommend some types of antidepressants if you are taking tamoxifen. These are fluoxetine or paroxetine. They may interfere with how well tamoxifen works.
The dose you have for hot flushes is usually lower than the dose used to treat depression. Remember that all drugs have some side effects. Anti depressants can cause a dry mouth, headaches, feeling sick, and loss of appetite.
Gabapentin
Gabapentin is a type of anti epileptic drug. It controls fits (seizures) but it can also help to reduce hot flushes.
In trials for women with breast cancer, it reduced the severity of hot flushes and how long they lasted.
Side effects of gabapentin include dizziness and drowsiness. Some women also develop a rash and fluid retention. We need more research to confirm how well these drugs work and find out more about side effects.
Clonidine
Clonidine is a drug used for a variety of conditions, including high blood pressure.
It can reduce the number of hot flushes. But it doesn’t reduce their severity or how long they last. Doctors usually recommend trying other treatments before starting clonidine.
Side effects include dizziness, a dry mouth, constipation, drowsiness, and difficulty sleeping.
Hormone replacement therapy (HRT)
One way to help control hormonal symptoms is to take hormones to replace the ones your body is no longer producing. 
is an effective treatment for many women. But some treatments for breast cancer aim to either stop the body producing sex hormones, or block their action. If you are having these treatments, you can’t unfortunately take HRT.
Doctors don’t routinely recommend that you take HRT if you have a cancer, such as breast cancer. Even if you have finished treatment there is concern that HRT may increase the risk of cancer coming back. Talk to your specialist if you are finding it difficult to cope with your symptoms. They can explain the risks and benefits of HRT and if this is an option for you.
Other therapies
Cognitive behavioural therapy (CBT)
This treatment suggests there is a link between your thoughts and actions. It focuses on calming your body and mind and keeping a positive outlook. Research suggests that this may help with hormonal symptoms such as hot flushes.
For example, one study found that CBT can reduce the effect of hot flushes and night sweats for women who have had breast cancer treatment. It helped women to feel better, sleep better, and have a better quality of life.
You can ask your doctor or specialist nurse whether CBT is available in your area.
Acupuncture
Acupuncture has been researched as a treatment for hot flushes in women. Studies have found that acupuncture can help to reduce hot flushes and sweats in women with breast cancer. The beneficial effects can sometimes continue for a few months after the course of acupuncture has finished.
These are generally small studies. Further research is needed to understand more about the benefits of acupuncture.
Some trials suggest that the following might help reduce hot flushes:
- yoga
- relaxation techniques
- hypnotherapy
Although these trials are encouraging, we need more research to understand how well they work.
Supplements
There are many supplements available for the relief of hot flushes. Generally, the evidence for their use is mixed or limited. But some women have found them useful.
It is worth bearing in mind that products can vary in terms of the dose and what they contain. And some may interact with other medicines you are taking, making these less effective or causing side effects. So always check with your doctor or pharmacist first.
Supplements include:
- vitamin E
- sage
- evening primrose
- gingko
- ginseng
Other supplements include phytoestrogens such as soy and red clover. And a herb called black cohosh. Phytoestrogens, and possibly black cohosh work in the body in a similar way to the hormone oestrogen. So it is not certain how safe these are for those who have breast cancer, or have had it in the past. So speak to your doctor if you are thinking of taking these.
Black cohosh interferes with the way tamoxifen works. So this should be avoided if you are taking tamoxifen for breast cancer.
Other products
Other products are promoted for the relief of hot flushes and sweats. For example, magnets that you wear in your clothing. Again, some women have said they have worked for them. But there is no evidence to prove they work.
