Every day, your body experiences a wide range of physical and psychological situations that it perceives as stressful.
Typically, we think of work, finances, or relationships when it comes to stress. But the list is much longer. Lack of sleep, dieting, and winning the lottery are also stressful! Why? Because all of these situations signal your body to produce cortisol.
Stress is helpful up to a point (because it helps you get your to-do lists done), but when your adrenals crank out cortisol chronically, they eventually become impaired in their ability to respond. The resulting adrenal imbalance not only zaps your mojo in a big way but also affects your body’s ability to produce and balance other feel-good hormones like DHEA, estrogen, progesterone, and testosterone. Your hormone symphony gets way off-key!
What’s the HPA Axis?
The hypothalamic-pituitary-adrenal axis, or HPA axis, describes the interaction between the hypothalamus, pituitary gland, and adrenal glands. The hypothalamus and pituitary gland are located just above the brainstem, while the adrenal glands are on top of the kidneys.
The primary function of the HPA axis is to control the body’s reaction to stress. When something stressful happens, the sympathetic nervous system mediates our initial response. This reaction is called “fight/flight/freeze.” This response occurs almost immediately and results in the secretion of epinephrine and norepinephrine, both of which work to create changes that you would generally expect if you felt stressed or frightened, like increased heart rate and perspiration.
About 10 seconds later, the HPA axis is stimulated. This creates a cascade of neurotransmitters and hormones, ultimately in the adrenal glands secreting cortisol. Cortisol has several effects on the body to help the body deal with a stressor that lasts longer than a few minutes.
For example, it increases blood pressure and cardiac output, providing more blood to your skeletal muscles in case the stressor you’re dealing with involves some sort of physical exertion (like running for your life). It also increases circulating glucose levels in your blood since glucose is a crucial energy source for your cells. This increase provides your body with extra energy to deal with the stressor.
How Does Stress Affect Your HPA Axis?
Cortisol acts during the experience of a severe stressor to inhibit processes that are of lesser importance at the time. These include altering your immune system responses, suppressing the digestive system, the reproductive system, and any growth processes. Once your body relaxes and flips into the parasympathetic nervous system (rest and digest), these functions return.
While proper functioning of the HPA axis is essential for dealing with stress, when the HPA axis is stimulated too much (for example, in someone who faces extreme stress daily), it can lead to physical and psychiatric problems. Repeated HPA axis activation has been linked to type 2 diabetes, obesity, and cardiovascular disease. Cortisol has detrimental effects on memory and thinking. Additionally, studies implicate high cortisol levels in mood disorders like depression.
Unfortunately, how your HPA axis responds doesn’t just depend on what’s happening in the present. Early-life experiences can affect the HPA axis’s baseline activity, and some studies suggest that early-life trauma may lead to an over-reactive HPA axis later in life. This overactivity may increase anxiety and potential metabolic effects, including excess fat deposition and insulin resistance.
How Does Perimenopause Fit Into the Equation?
As you enter perimenopause, you may find you don’t cope as well with stress. It happens because losing progesterone during perimenopause can destabilize the HPA (adrenal) axis or stress response system.
This nervous system recalibration is why perimenopause is associated with an increased risk of anxiety, depression, and insomnia. Progesterone is not just a reproductive hormone. It’s also a brain and nervous system hormone.
Progesterone does two crucial things in the brain:
- It promotes neurogenesis (new nerve growth) in a part of the brain called the hippocampus, the main regulator of the HPA (adrenal) axis.
- It converts to the beneficial neurosteroid allopregnanolone (ALLO), which calms GABA receptors.
The result is that progesterone promotes neurogenesis and GABA and increases the capacity to cope with stress. Losing progesterone will make it harder to cope with stress, but only until your HPA axis can recalibrate. After that, you should recover your ability to cope with stress.
Dr. Anna Garrett is a menopause expert and Doctor of Pharmacy. She helps women who are struggling with symptoms of perimenopause and menopause find natural hormone-balancing solutions so they can rock their mojo through midlife and beyond. Dr. Anna is the author of Perimenopause: The Savvy Sister’s Guide to Hormone Harmony. Order your copy at www.perimenopausebook.com.
Also, she offers a membership group, Hormone Harmony with Dr. Anna Garrett, which provides women in midlife with affordable expert guidance and community support.
Dr. Anna is available for 1-1 consultation. Find out more at www.drannagarrett.com/lets-