If You're Tired All the Time, These Are the Most Important Tests to Ask Your Doctor For

Waking up in the morning and pressing the snooze button three times before you actually climb out of bed. Hitting an afternoon slump and relying on another cup of coffee to get you through the day. Feeling tired but wired at night, exhausted yet unable to sleep. These are all feelings that are so common that they’ve become normalized—but that doesn’t mean it’s the way it should be.

The truth is, we aren’t meant to feel tired all the time. If you find yourself feeling sluggish and run down on a regular basis, it’s worth it to book an appointment with your healthcare provider to pinpoint the root cause. In order to advocate for your health effectively, it’s important to know what to ask for when you’re there. This is especially important for women and people of color, whose health complaints, at times, are not taken seriously by doctors.

“If someone is feeling sluggish, the most important thing they should ask a doctor for isn’t one test but rather a detailed medical history to uncover why, along with a panel of focused tests to support or add to it,” says Dr. Elliot Dinetz, MD, a board-certified family medicine doctor and functional medicine doctor.

Internal medicine doctor Dr. Nesochi Okeke-Igbokwe, MD, MS, agrees, saying that if someone is feeling sluggish on a regular basis, they should discuss all their symptoms with their healthcare provider. “The doctor will obtain a full medical history from the patient, conduct a physical examination, and proceed to order any appropriate tests. After a comprehensive assessment, certain common laboratory tests may be ordered. Depending on the full clinical picture, there may be a need for a more extensive workup,” she explains.

With this in mind, there are a few important blood tests you'll want to make sure your doctor performs. Here, Dr. Okeke-Igbowe and Dr. Dinetz list the most important ones.

Related: Wondering Why You're Always So Tired? Here Are Some Clues—Plus, the Best Ways to Boost Your Energy

5 Tests To Ask Your Doctor for if You're Feeling Sluggish

1. Complete blood count (CBC)

Dr. Okeke-Igbowe says that this test is important because it can reveal if someone is anemic, which can cause prolonged fatigue. Besides feeling sluggish, she says that feeling weak and short of breath are also symptoms of anemia.

The most common cause of anemia is not getting enough iron and vitamin B12. That means that the majority of the time, it’s treatable by making changes in your diet. Sometimes, however, anemia is caused by another chronic health condition. If this is the case, it’s important to continue to work with your healthcare provider to treat the underlying condition.

2. Thyroid test

“Thyroid conditions such as hypothyroidism may lead one to feel sluggish and weak,” says Dr. Okeke-Igbowe, emphasizing the importance of getting your thyroid levels checked. Hypothyroidism affects roughly five percent of Americans and people who have had a thyroid issue in the past, have a family history of thyroid disease, or who have been pregnant in the last six months are most at risk. Besides fatigue, other symptoms include weight gain, feeling cold, joint and muscle pain, thinning hair, dry skin and a slowed heart rate.

Like anemia, hypothyroidism can be caused by an underlying chronic condition. Getting to the root cause is key for proper treatment.

Related: Struggling to Lose Weight With Hypothyroidism? These 7 Nutritionist-Approved Tips Can Help 

3. Vitamin D levels

Both Dr. Dinez and Dr. Okeke-Igbowe say that not getting enough vitamin D can make someone feel fatigued. Roughly 42 percent of people in the U.S. don’t get enough vitamin D. Here’s the good news: if you know you’re deficient, you can take action and remedy the problem by either spending more time in the sunshine or taking a supplement.

4. Hemoglobin A1C (HbA1C) test

“This test measures the average blood sugar levels over the past three months and can aid in diagnosing diabetes,” Dr. Okeke-Igbowe says, adding that one common symptom of diabetes may be fatigue. An estimated one in 10 Americans has type 2 diabetes, which can be caused by genetics, a diet high in sugar, smoking and obesity. Diabetes is a serious condition, so it’s important to work with your healthcare provider to manage it if your HbA1C test indicates that you have it.

Related: 13 Foods That Help With Diabetes, from Raspberries and Blueberries to Tuna and Brussels Sprouts

5. Cortisol test

When Dr. Dinetz has a patient who is feeling sluggish, he is sure to test their cortisol levels. Known as the “stress hormone,” chronically high cortisol levels can make someone feel tired, get headaches, experience digestive problems, have trouble concentrating and gain weight. It is possible to bring high cortisol levels down through diet and lifestyle habits and once you do, you can expect to feel more energized.

“The bottom line is that if you experience ongoing weakness and lethargy, it is key to be evaluated by your doctor to determine the underlying cause and proceed with the appropriate plan of care,” Dr. Okeke-Igbowe says.

As she makes crystal clear, the best way to start feeling more energized is to figure out the root cause of why you’re so tired in the first place—and that’s exactly where these tests come into play. Armed with knowledge and a proper treatment plan, you’ll be on your way to feeling your best, more energized self.

Next up, check out this list of 13 possible reasons for afternoon fatigue.