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Why am I always so tired?

September 20, 2018 | UCI Health
man who is very tired at work

“I’m always so tired — it’s a complaint doctors hear all the time,” says David Sodaro, MD, a UCI Health family physician. “I hear it from nearly every one of my patients at one time or another.”

But the cause of fatigue could be anything under the sun, including anemia, depression, insomnia, something they ate, chronic fatigue syndrome — even cancer — which makes it hard to zero in on a treatment plan.

Digging for root causes

“We have to be energetic about finding the causes,” Sodaro says. “Emotional or stress-related fatigue is very different from tiredness resulting from anemia or cancer, and sometimes they overlap.”

To determine what’s causing fatigue, doctors usually take a detailed history, asking a lot of questions that will lead them down one path or another, ever alert for red flags to help discover the root cause. They ask about:

  • Diet
  • Lifestyle
  • Significant unexplained weight loss
  • Bleeding
  • Pain 
  • How long the patient’s tiredness has persisted

“Fatigue is ubiquitous,” Sodaro says. “We have to approach it on a case-by-case basis,”

Ruling out medical problems

Sodaro first tries to rule out medical problems.

Additional symptoms such as excessive thirstiness might indicate type 2 diabetes. Joint pain could be indicative of rheumatoid arthritis. Or patients might recently have experienced head trauma or a bout of influenza.

Laboratory tests also help doctors uncover medical reasons for fatigue:

  • Hemoglobin analysis could indicate anemia
  • Differential levels of white blood cells might reveal a chronic illness
  • Thyroid-stimulating-hormone (TSH) levels can indicate a thyroid problem
  • High levels of blood glucose could be a sign of diabetes or prediabetes

If medical problems are ruled out, Sodaro says he looks at for any undiagnosed psychiatric problems, such as depression, anxiety or bipolar disorders. All can cause significant fatigue. But these issues may also accompany a medical diagnosis.

Log your tiredness levels

Next, doctors explore emotional stress. They may ask you to make a fatigue inventory to asses when tiredness occurs and what makes it better.

  • Are you stressed at work?
  • Do you have a new job or school?
  • Have you changed your diet?
  • Are you fighting with your spouse or mother?

Part of any stress inventory is analyzing what makes it better, or not. For example, are you revived by sleeping in on Sunday morning after a night of revelry? Does your stress disappear on the weekends once you’re away from work? Do you still feel exhausted after a weeklong vacation?

All these things can factor into understanding and eliminating fatigue. Sodaro says one of his patients suffered debilitating migraine headaches that didn’t respond to a variety of treatments over eight years, yet they disappeared entirely once she moved to a lower-stress job.

The art of diagnosing fatigue

It’s an art to uncover the cause of fatigue in patients young and old. In adolescents and young adults, there’s less worry that the cause is disease, says Sodaro, who has years of experience to call on. In middle-aged patients, disease becomes more of a factor. Many seniors may have chronic conditions that can contribute significantly to tiredness.

Still, excessive tiredness can reveal a medical problem at any age. “We have to be alert,” he says.

“Most of the fatigue we see in young people results from them simply doing too much. But a 19-year-old vegan might be suffering from anemia. A fit football player’s fatigue and night sweats might make me think of a systemic disease like lymphoma.”

No matter what, if you experience serious fatigue, Sodaro advises that you bring it up with your primary care doctor and expect to get a complete examination.

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