On any given Monday morning, most of us struggle to get out of bed as we dread the inevitable work week. We yawn, we stretch, and we drift in and out of sleep. Throughout the day, we feel exhausted both mentally and physically. The Sunday Night Blues or a lack of sleep aren't the only things sapping our energy — sleep loss could be a sign of several serious illnesses.

Our 24/7 lifestyle can lead us to feel exhausted or run down, and affect our sleeping patterns. This is because “we are never turning off” according to Dr. Gabrielle Francis, a naturopathic doctor at The Herbal Alchemist in New York City, N.Y. “This syndrome is also known as ‘wired and tired,'" she told Medical Daily.

Fatigue is an American epidemic that is one of the most common complaints physicians hear. It is quite prevalent in the general population, with 28 percent reporting fatigue. This could be the result of expending more energy than we can take in, but it could also be a red flag for more serious conditions.

Below are the signs of fatigue we shouldn't ignore.

Sleep Apnea

The feeling of being "dead tired" may be attributed to how soundly we sleep at night. Snoring is a common characteristic of sleep apnea, which affects more than 18 million Americans. Obstructive sleep apnea, the most common of three types (i.e., central, mixed) occurs when soft tissue in the back of the throat collapses and obstructs the airway, causing us to repeatedly stop breathing during sleep. This is excessive daytime sleepiness — when we fall asleep easily and sometimes inappropriately, with loud snoring.

The disorder prevents us from getting enough oxygen during sleep, which is why we won't get real rest during the night. The brain notices you're not getting rid of CO2 and often wakes you up briefly in an alarmed state


Feeling sluggish, irritable, weak, or unable to focus could be a sign of an iron deficiency, or anemia. The disorder makes it difficult for blood to move oxygen around the body because it decreases the number of red blood cells so that insufficient oxygen is getting to the cells for energy production.

"When you have decreased oxygen going to your brain & to all of your muscles & organs, you feel fatigued" Dr. Donnica Moore, a physician trained in gynecology and women's health, told Medical Daily.

Thyroid Problem

The thyroid is commonly known to regulate our metabolism, specifically metabolic rate. Anything that reduces thyroid hormone production will lower the metabolism to conserve energy, making us feel constantly tired.

"If minerals like magnesium, manganese, selenium or iodine are low, the thyroid cannot make enough hormone and fatigue will set in," Dr. Scott Schreiber, a chiropractic physician, double board certified in rehabilitation and clinical nutrition in Newark, Delaware told Medical Daily.

Heart Disease

The heart is the pump for the circulatory system, so if the heart is compromised, it will not pump efficiently or circulate well, leading to fatigue. This is a common symptom in congestive heart failure. Exercise intolerance and fatigue are the most common symptoms of heart failure.

“As a result, the body diverts blood from lesser important areas like the limbs, so that it can protect the most vital organs (eg heart, lungs, brain),” she said.

Many people with heart disease take medications that cause fatigue as a side effect.


Women who hit menopause will often cite bouts of tiredness as a symptom. Menopause is also accompanied by a decrease in metabolism. The incidence of hypothryoidism (low-acting thyroid) greatly increases after menopause, and continues to do so with increased age.

Moore notes: “Changing hormone levels (estrogen, progesterone, thyroid and adrenal hormones) which are all involved in regulating cellular energy in the body, can also contribute to fatigue.”