Top 9 Causes of Fatigue
Find out what typically causes fatigue and how your doctor figures out why you’re so tired.
56-year-old Frank came to see me in the clinic with his wife who said she had to “drag” him to my office. Frank has been tired all the time for the past 2 months and just can’t seem get motivated enough to get out of the house. Frank says that he just “hates the doctor’s office,” which is why he hasn’t been to one in over a decade.
Fatigue is likely one of the top 20 complaints that I hear from my patients. Living in today’s hectic world, we are all overworked and overstressed and this is one of the most common causes of fatigue. Sometimes the stress can just catch up to us and cause our bodies to want to shut down and rest. But before we blame Frank’s fatigue on stress, it’s my job to make sure it’s not anything more serious.
The History
Before I make any conclusions about Frank’s condition, I need to ask him some questions to really dissect the situation. So I start taking what doctors call the “patient history” and I ask him about:
-
Medications
Some medications, like those prescribed for blood pressure, can cause fatigue as a side effect. Frank hasn’t seen a doctor in over 10 years, let alone taken any medications. He also denies taking any over-the-counter supplements or herbal remedies. -
Alcohol/Drugs
Excessive alcohol intake and illicit drug abuse often runs through my mind as a possible cause of fatigue, but Frank tells me he drinks one glass of red wine with dinner maybe once a week and that he’s never dabbled in any drugs. -
Depression
One of the most common ways patients with depression present at the doctor’s office is with complaints of fatigue. Often, patients are so depressed that they don’t want to go out or do the things they used to enjoy; doctors call this “anhedonia.” When I ask my patients with fatigue if they are depressed, they sometimes break down crying (this is why I always make sure to stock a box of tissues in each one of my exam rooms). Frank tells me that although he’s had more stress at work, he’s never been happier. -
Excessive Caffeine
Those who drink excessive caffeine often get a burst of energy initially, but then may crash after the effects wear off. Frank says he drinks 1 cup of coffee in the mornings, and stays away from sodas and energy drinks. -
Thyroid Disease
Hypothyroidism, where the thyroid is underactive and produces too little hormone, can slow down the metabolism and cause fatigue. It is often hereditary, but Frank says that no one in his family suffers from this ailment. -
Anemia
I always ask about heavy periods in women, and any bleeding in the stool or elsewhere in both men and women with fatigue. This is because anemia is also on my list of possibilities anytime a patient complains of fatigue. If our red blood cells don’t have enough iron, they can’t carry oxygen properly, causing us to feel tired. Frank denies seeing any blood in his stools.
-
Heart and Lung Problems
Certain heart and lung problems can also cause fatigue. Frank denies any shortness of breath, cough, heart palpitations, or chest pains. -
Sleep Apnea
People with sleep apnea often snore and have brief moments in which they stop breathing during sleep. This is often witnessed by their spouses and can be very scary. These patients often experience daytime fatigue, and report frequent napping. Frank’s wife says that although Frank does snore on occasion (which she finds a tad annoying), she’s never seen him stop breathing. -
Sleeping Disorders
Insomnia or certain sleep disorders, like Restless Leg Syndrome, can interfere with a good night’s rest. We may not feel refreshed upon awakening, and this can cause daytime fatigue. Frank denies any issues with his sleep.
The Physical Exam
After taking a detailed patient history, next comes the physical exam. On exam, I noticed that Frank looked a tad pale, although the remainder of his exam was normal.
Diagnostic Labs
What is going on with Frank then, you may ask? Well, whether or not the doctor may have an idea of what’s causing the fatigue, we will likely run some tests, including one for the thyroid and one for anemia. There are other rare causes of fatigue, like liver and kidney disease, and leukemia (although these are quite rare), and your doctor will likely check these items as well.
So what did I find in Frank’s labs? His hemoglobin, the test that indicates anemia, was 10.2. Normal hemoglobin for women is above 12.0 and men above 14.0. So Frank is pretty anemic and that is what’s making him so tired.
But as a physician, I can’t just stop there because I know it’s not normal for a man his age to be so anemic. I needed to find out exactly what was causing Frank’s anemia. So I had his stool tested to check for bleeding. The test did indeed show some microscopic blood in his stool that is not visible to the naked eye. I then sent Frank to have a colonoscopy, a screen for colon cancer that is routinely done for people aged 50 and over. And I knew that Frank never had a colonoscopy since he hadn’t seen a doctor in so long.
The Diagnosis
Unfortunately, the root cause of Frank’s anemia and blood loss was a bleeding polyp that came back as cancerous. He needed surgery to have a part of his colon removed. Thankfully, because we caught it early on, he is in remission and doing swell. Frank tells me that he will never again put off his routine preventative care, even though he “still hates the doctor’s office.”
The cause of fatigue is not always so serious as it was in Frank’s case. Most of the time, my patients’ labs come back normal. However, it’s still one of those symptoms that should not be ignored.
Please note that all content here is strictly for informational purposes only. This content does not substitute any medical advice, and does not replace any medical judgment or reasoning by your own personal health provider. Please always seek a licensed physician in your area regarding all health related questions and issues.
Fatigue image courtesy of Shutterstock
About the Author
Dr. Sanaz Majd is a board-certified Family Medicine physician who graduated from Drexel University College of Medicine in Philadelphia. Her special interests are women’s health and patient education.
