Vasomotor symptoms (VMS): understanding your hypothalamus

Perimenopause, also known as menopausal transition, refers to the years leading up to menopause, the date that is considered the end of the reproductive years for the female reproductive system. Menopause begins after 12 consecutive months without a menstrual period.

During perimenopause, the female reproductive system will begin to produce less estrogen, a hormone that plays an important role in sexual development and reproductive function in females. These declining levels of estrogen eventually result in menopause.

Declining levels of estrogen also affect the functioning of many other parts of the body, including a part of the brain called the hypothalamus.

The hypothalamus

The hypothalamus is located in the center of the brain. It’s the part of the nervous system that regulates the production, release, storage, and regulation of the body’s hormones. This includes hormones that control heart rate, sleep, mood, hunger, thirst, libido, and body temperature.

The hypothalamus and hot flashes

Because the hypothalamus regulates body temperature, it is sometimes referred to as the body’s “thermostat.”

The declining levels of estrogen that occur during perimenopause affect how the hypothalamus responds to changes in temperature. These changes are behind the most common symptoms experienced by people during perimenopause—vasomotor symptoms (VMS), more commonly known as hot flashes and night sweats.

Changes in the hypothalamus during perimenopause cause the nervous system to overreact to slight changes in temperature. This overreaction causes the body to activate the mechanisms it uses to cool itself down. Blood vessels widen to allow more blood to flow to the surface of the skin (a mechanism called vasodilation), which results in heat loss. The term “vasomotor” refers to the narrowing and widening of blood vessels. Flushing skin, warmth that spreads through the chest, neck, and face, and sweating are typical symptoms during a hot flash.

The hypothalamus and VMS treatments

Anyone experiencing VMS should discuss their symptoms with a healthcare provider, especially if VMS are interfering with things like relationships, work, sleep, or other important aspects of life and health. There are treatments that can help manage VMS as well as other menopause-related symptoms.

Treatment for VMS falls into two broad categories, therapies that involve taking hormones and therapies that do not involve taking hormones.

Non-hormone VMS medications

Several non-hormone medications are approved by the U.S. Food & Drug Administration (FDA).

One is a drug that blocks a neurotransmitter in the hypothalamus called neurokinin B (NKB). Neurotransmitters are chemical messengers that send signals between nerves. Reducing the activity of NKB helps regulate activity in the hypothalamus, helping to reduce VMS.

Another FDA-approved medication for VMS is a low dosage of a type of antidepressant called an SSRI (selective serotonin reuptake inhibitor). SSRIs have been used off-label treatment of VMS even before this drug’s approval. SSRIs are believed to reduce VMS by regulating activity in the hypothalamus and counteracting the vasodilation in blood vessels near the skin, though the mechanisms are not fully understood.

Hormone therapy

Hormone therapy involves taking medications that restore levels of the hormone estrogen (and in some cases, the hormone progesterone as well). Hormone therapy is believed to help regulate activity in the hypothalamus. Hormone therapy can be very effective in reducing VMS.

Discuss side effects with a healthcare provider

Some people may need to avoid hormone therapy due to the risk of side effects, which can include an increased risk of blood clots and stroke, and breast cancer. The risk of side effects from hormone therapy varies depending on the drug, dosage, and a person’s medical history.

Non-hormone medications also carry a risk of side effects. Before starting any medication, it’s important to discuss side effects, risks, drug interactions, and any other concerns with your healthcare provider.

Managing VMS

Different approaches to managing VMS will work better for different people, and your best source of information will be your healthcare provider.

Lifestyle modifications such as maintaining a healthy weight, exercising, reducing stress can also help a person manage VMS. It also helps to be prepared when a hot flash occurs—dressing in layers that can easily be removed, having a portable fan, and having a cold drink of water nearby can help ease symptoms when you need to.