Your body is telling you something. There are many potential causes of fatigue. But one thing is clear: you don’t just randomly show up with no energy to do anything. Your body’s resources have become depleted, and it’s time you figure out why. That may mean visiting a different doctor or reflecting on your lifestyle.

Fatigue that lasts more than a couple of weeks and isn’t explained by an obvious cause warrants a medical appointment. 

Unfortunately, conventional medicine falls short at investigating fatigue. Because there are so many possibilities to sort out in the usual 10-15 minute office visit, most doctors take a superficial approach. In the end, if you tell your doctor you have no energy, you may end up with a prescription for a stimulant or an antidepressant. Or maybe, your doctor tells you, “You just need to slow down.”

How do you slow down when you are already dragging?

Fatigue has many causes: some are simple (“I didn’t sleep well last night”) while others are more complex (“I have an ongoing autoimmune disease”).

It may take some time and testing to figure out what is causing your fatigue. Many times it isn’t one thing. You will need to work with a functional medicine clinician who will evaluate physical, emotional, and lifestyle contributions. Their goal (and your goal) is to figure out the root cause of your fatigue and get you feeling like yourself again.

The most common causes of fatigue in my practice

1. Adrenal fatigue (also known as HPA Axis Dysregulation). When you are under stress, your adrenal glands release adrenaline, noradrenaline, and cortisol, your body’s stress hormones. Adrenaline and noradrenaline manage your flight-or-fight response, and in times of danger, it’s critical. If you need to run from a house on fire, your adrenal glands will help you maintain the presence of mind to save yourself and those you love. If you happen to be injured in the fire, cortisol will help you heal those wounds effectively. But, you don’t want cortisol pumping through your veins at high levels, every day, all the time. Too much cortisol disturbs almost every bodily function, including sleep, sugar metabolism, and hormone function. Eventually, with prolonged stress, cortisol levels can become imbalanced, and severe, unrelenting fatigue follows, a.k.a. no energy.
2. Low thyroid function (hypothyroidism). The role of thyroid hormone is to set the “pace” for all of the body’s functions. It makes sense that a low functioning thyroid feels like someone just turned down every dial in your body. Fatigue is one of the most common symptoms of hypothyroidism, along with weight gain, hair loss, dry skin, constipation, and palpitations.
3. Perimenopause. When female hormones start to wane in perimenopause, it can mess with your sleep (most often because of a progesterone deficiency). Having frequent awakenings during the night, and difficulty going back to sleep, will most certainly cause fatigue.
4. Nutritional deficiencies. Even if you consume a decent diet, the nutritional value of many foods has changed over the years, making it more difficult for some of us to get the right balance of nutrients from the foods we eat. Throw in a genetic predisposition to an inefficient use of nutrients in the body, and you have yourself a nice recipe for fatigue! Most doctors will check the obvious nutrients (like iron and B12), but to really understand the full picture, a more in depth evaluation is necessary.
5. Poor sleep hygiene. Many of us are guilty of falling asleep with our smart phones in hand or with the TV on. Or we go to bed at different times every night, sometimes falling asleep on the couch. These poor sleep habits disrupt our normal circadian rhythm, leading to poor quality sleep. We may be getting 7-8 hours of sleep, but they are not restorative ones.
6. Caffeine or alcohol use. A lot of people are quite sensitive to caffeine, lacking the genetics to process it well. If we drink caffeinated beverages too close to bedtime, we may have difficulty falling asleep. As we slog through our day, we may rely on caffeine to get us through, putting additional stress on our adrenal glands. Similarly, alcohol can be very disruptive to good sleep, causing shifts in blood sugar, and waking us up when the alcohol leaves our system.
7. Sleep apnea. When the soft palate portion of the back of our throat temporarily cuts off our breathing, we experience an apnea episode. This is more common in people with nasal obstruction (allergies, deviated septum), or obesity (the weight of the neck presses down on the throat). Sometimes we are jarred awake by the episode, but other times the apnea doesn’t fully wakes us. However, it keeps us from falling into deep, restorative sleep.

What you can do

While this is an obviously incomplete list of causes, it is important to discover why you are tired. Your health and happiness depend on it.

If you are unable to sort out the causes of your fatigue on your own, it’s best to get a full evaluation. A functional medicine practitioner will check the appropriate tests for things like a nutritional deficiency and your hormone levels. They’ll also work with you to sort out the lifestyle habits that are depleting your energy levels. You don’t have to live with debilitating fatigue.