We’re a nation of sleepyheads. Up to 15% of Americans struggle with extreme fatigue, according to the U.S. Centers for Disease Control and Prevention and one international study found an estimated 30% of all visits to the doctor were related to feeling tired all the time.
For those getting less than the recommended 7–9 hours of sleep per night, adjusting your sleep schedule to spend more time in bed could ease symptoms of fatigue such as headaches, moodiness, aching muscles and dizziness. If you’re tucked in from 10 p.m.–6 a.m. and still struggle with overwhelming exhaustion, it could be time to see a doctor because one of these four underlying medical issue could be to blame.
When your blood carries too little oxygen, a condition called anemia, it can leave you feeling tired, cold, dizzy and short of breath. An estimated 5 million Americans are anemic. The most common causes include lack of iron, heavy periods and pregnancy.
A simple blood test can detect the condition, notes registered dietitian Erin Palinski-Wade. If your iron levels are low, your doctor may recommend supplements or a diet containing iron-rich foods such as red meat and seafood. Though a 2017 study found vegetarians were more apt to be anemic than meat eaters, Palinski-Wade points to several plant-based foods that are high in iron, including lentils, black beans and spinach.
“Combining iron-rich foods with a source of vitamin C can also increase absorption so try making a spinach salad topped with lentils and strawberries for a plant-based, iron-rich meal,” she says.
You might have sleep apnea and not even know it. It’s often a partner who spots symptoms, such as loud or chronic snoring and gasping for air in your sleep, according to Dr. Dan Root, board-certified sleep specialist and founder of Oregon Sleep Associates. Sleep apnea causes repeated pauses in breathing throughout the night — sometimes up to 100 times.
“When people with sleep apnea awaken, they commonly do so with more adrenaline than those without sleep apnea, so they are more likely to be more alert [and] that can make it harder to go back to sleep,” Root says.
Don’t brush off complaints about severe snoring, especially if you’re overweight or obese — common risk factors for sleep apnea. Research published in the Journal of Clinical Sleep Medicine linked the condition to an increased risk of stroke and cancer.
Depression is exhausting. In a 2018 study, fatigue affected more than 90% of those with major depressive disorder. Even mild depression can make you feel tired and, according to licensed professional counselor Stacee Reicherzer, PhD, “Fatigue is often our [warning] symptom that we’re starting to slip into a period of depression.”
Sleep problems, including poor sleep quality, are hallmark symptoms of depression. One study linked fatigue to greater severity of depression.
In addition to fatigue, those with depression also experience sadness, loss of interest in activities, trouble concentrating and poor appetite. Seeking treatment can help boost your mood and improve your sleep quality, leaving you feeling energized, not exhausted, notes Reicherzer.
An underactive thyroid gland could be the reason you’re tired all the time. Hypothyroidism interferes with the production of thyroid-stimulating hormone or TSH. “The thyroid gland is part of metabolic control. Simply put, when [the gland] is not making enough hormone, it slows everything down,” Root explains. Fatigue is the most common symptom but hypothyroidism can also cause dry skin, weight gain, muscle weakness and depression.
New research published in the journal Frontiers in Endocrinology found low levels of thyroid hormones were associated with chronic fatigue syndrome, a condition associated with fatigue, weakness and depression. Root notes that treating hypothyroidism, often with medication to restore hormone levels, helps alleviate fatigue.
If you get restful sleep most nights and still spend your days feeling overwhelming fatigue, call your doctor.