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Why Am I So Tired?

by Nadia B. Pietrzykowska, MD, FACP

Summer 2017

This is probably the most common complaint that I hear from new patients coming to see me for weight management. Fatigue can range from mild to very severe, and can even be debilitating enough to significantly decrease quality of life.

There are several possible conditions that can cause fatigue and they should be diagnosed and treated accordingly. Some of those conditions are hormone abnormalities, nutritional deficiencies, mental health conditions and other diseases.

Thyroid Disorders:

The thyroid is a gland located in the neck that is responsible for producing hormones involved in energy metabolism. An underactive thyroid results in the slowing of metabolic processes that can range from mildly noticeable to life-threatening. Testing thyroid function is part of a yearly routine physical exam.

Hyperthyroidism is a condition in which the thyroid gland doesn’t produce enough thyroid hormone. Common symptoms of hypothyroidism include, but are not limited to:

  • Fatigue
  • Weight gain
  • Cold sensitivity
  • Constipation
  • Brittle nails

Thyroid testing should be performed to assess thyroid function if these symptoms are present. When laboratory tests are abnormal, your doctor will determine the causes of hypothyroidism and prescribe treatment. “Borderline” thyroid function may also need to be treated if the clinical symptoms are very typical. In some cases, thyroid dysfunction is part of more complex medical conditions that include multiple hormone-producing organs, and when diagnosed, they should be treated by an endocrinologist.

Insulin Resistance and Metabolic Syndrome:

A large amount of patients coming to see me for weight gain also have some form of abnormal glucose metabolism such as:

  • Insulin resistance
  • Prediabetes
  • Diabetes

Explaining the differences between these would be beyond the scope of this article, but it is important to know that both high and low blood sugar levels can cause fatigue. If diagnosed, these conditions should be treated. Prediabetes is a medical condition that should be treated aggressively before it leads to diabetes. However, it can be reversed with weight-loss as small as 10 percent.

Metabolic syndrome consists of multiple symptoms which may include abnormalities in blood pressure, cholesterol, blood sugar and abdominal adiposity. If your physician diagnoses you with insulin resistance or metabolic syndrome, you may need medication to treat it. Excessive weight and metabolic syndrome are connected, and treating them is very important. With treatment, patients report feelings of increased energy and less “highs and lows” during the day when compared to before treatment.

Adrenal Gland Disorders:

These are generally rare and can include disorders that result in either underactivity or over-activity of the adrenal gland. Some of these disorders are also linked to obesity, and your physician may order a specialized workup or refer you to an endocrinologist to further investigate and treat these conditions.


Peri-menopausal women often complain of fatigue. Changing hormone levels around menopause may be the culprit, especially with estrogen. Decreasing estrogen levels may result in increased fat mass, decreased muscle mass and abdominal adiposity, which altogether can result in fatigue. Proper diet and physical activity may help prevent this from occurring. Hormone replacement therapy is generally not recommended for the treatment of fatigue-related symptoms linked to menopause.

Andropause and Low Testosterone Levels:

Inappropriately low testosterone levels may result in fatigue. Unfortunately, the topic of testosterone replacement remains controversial due to possible adverse effects and unclear benefits.


Red blood cells transport oxygen from the lungs to all body organs. When the number of these blood cells decreases, this is called anemia and it often appears as fatigue. Your doctor will investigate to ensure that this is not the result of undiagnosed, slow blood loss from any gastrointestinal source. If there’s no bleeding, the most common causes of anemia are iron deficiency and vitamin B12 deficiency. These are discussed next.

Nutritional Deficiencies:

Individuals trying to lose weight often follow diets that are not necessarily “healthy” and may result in nutritional deficiencies. In addition, it is also known that individuals affected by obesity may consume high-calorie, low nutrient foods that can also result in nutritional deficiencies. Some patients may follow restricted diets for religious or personal reasons. Any dietary deficiency can manifest as fatigue.

Iron deficiency and vitamin B12 deficiency – These deficiencies can be present and cause fatigue even if anemia does not exist yet. Your healthcare provider will order appropriate blood tests to look for these abnormalities and treat them with supplementation. Among patients with excess weight, those with restricted diets or a history of bariatric surgery are most prone to these deficiencies.

Vitamin D deficiency – The topics of vitamin D and supplementation spark controversy and debate. This said, individuals affected by excess weight often have low vitamin D levels and fatigue. Therefore, this deficiency should be treated and may help resolve symptoms.

Lack of Physical Activity:

As individuals gain weight, they are often less active due to physical restrictions. This can lead to weight gain and the loss of muscle mass, thus resulting in reduced stamina and fatigue. Physical activity should be resumed gradually to ensure safe and injury-free progress to a healthier body.


Sometimes fatigue can be confused with depression. It’s very important that you report to your clinician if you are experiencing symptoms of depression such as:

  • Feelings of sadness
  • Loss of interest or pleasure in activities
  • Changes in sleep, appetite, or concentration
  • Social isolation

Depression is a serious psychiatric condition that needs to be treated as soon as possible. In cases with depression, fatigue may improve when depression is treated.

Sleep Disorders:

Obstructive Sleep Apnea: Weight gain may cause a medical condition called obstructive sleep apnea. Patients typically snore at night, may gasp for air during sleep, have restless nights, wake up with headaches or feel a lack of rest after a night of sleep. They are also sleepy and tired during the day. This condition is the result of inadequate brain oxygenation at night and interrupted or non-existent “deep sleep.” This is a serious condition that needs to be evaluated and treated by a sleep medicine specialist. It typically improves or resolves with weight-loss.

Other sleep abnormalities: In addition to obstructive sleep apnea, there are several sleep disorders that may affect sleep and prevent rest at night. Commonly, this results in perceived fatigue during the day. Whenever an individual does not get a good night’s sleep and does not feel rested during the day, this should be investigated.

Inadequate sleep hygiene: In our society, sleep is not taken seriously enough. The demands of daily life paired with busy work schedules affect individual health. In addition, poor sleep hygiene that includes staying up late, watching television and working on a computer late at night may prohibit proper rest and result in fatigue. It is a good idea to take a minute and think about your sleep hygiene. Sometimes, minor changes like going to bed at the same time every night and designating your bedroom only to sleep can help improve fatigue significantly.

Decreased Metabolic Rate or “Slow Metabolism”:

Many of the medical conditions discussed above can result in a slower metabolism. However, there are other conditions that can slow your basal metabolic rate as well:

  • Low muscle mass: This is common and happens with aging, but an exercise regimen that includes resistance training can help preserve muscle mass. This will not only help maintain a healthy metabolism and appropriate energy levels, but it will also promote healthy aging and decrease cardio metabolic risk.
  • Inappropriate eating habits: Skipping meals, eating poor diets, etc., may also decrease your metabolic rate.

Chronic dieting: Patients that are always on a diet tend to be fatigued. This is most likely caused by a slowing of their metabolic rate, often resulting from chronic caloric restriction and possible nutritional deficiencies.

Food Sensitivities:

Blaming all of our issues on food allergies and sensitivities is based more on hype than on fact. This said, sometimes patients can identify specific foods that make them feel bloated, uncomfortable or tired. A simple test where the food in question is eliminated can resolve the issue. However, it’s recommended that you discuss this with your healthcare provider to ensure that your diet remains balanced and appropriate because food restriction may result in nutritional deficiencies.


Various medications can also contribute to fatigue as well. Some examples may include:

  • Certain types of blood pressure medications
  • Some cholesterol medications
  • Psychiatric medications
  • Antihistamines
  • Medications used for acid reflux

If you believe that some of your medications are causing fatigue and/or weight gain, talk to your doctor to see if you may be able to find alternatives. Do not discontinue any medication on your own as this may be harmful to your health.


This is a medical condition characterized by generalized musculoskeletal pain as well as issues with mood, sleep, memory and fatigue. This misunderstood condition is more common in women than in men, and treatment may include medication, physical and occupational therapy, counseling and some alternative treatments such as acupuncture.

Chronic Fatigue Syndrome:

This is a serious medical condition that presents with severe chronic fatigue and additional characteristics including:

  • Loss of memory or concentration
  • Headaches
  • Sore throat
  • Enlarged lymph nodes typically in the neck or armpits
  • Unexplained muscle pain
  • Joint pain that moves from joint to joint
  • Unrefreshing sleep
  • Extreme exhaustion after mental or physical exercise

This medical condition needs to be examined thoroughly to ensure that it is not confused with any other medical problem. Unfortunately, there are only experimental treatments for this chronic condition.

Chronic Autoimmune Diseases:

This group of ailments manifests when the body starts attacking its own cells. There are many different types of autoimmune diseases and they are generally chronic in nature, so they commonly present with unexplained fatigue. When suspected, your doctor will refer you to a rheumatologist who can order a diagnostic workup and treatment.


New and unexplained fatigue needs to be treated seriously, especially if paired with unexplained weight-loss. Always talk to your doctor if you experience these symptoms to ensure that any serious underlying condition is diagnosed and treated.


I like to treat fatigue seriously, and I feel that it is often underdiagnosed and undertreated. Commonly, patients will say “I am tired because I am overweight” or “I am getting old.” I would not settle on this explanation until a proper medical investigation has been completed, as most patients can get help and improve their fatigue and quality of life with proper treatment.

About the Author:
Nadia B. Pietrzykowska, MD, FACP, is a Board Certified and Fellowship trained Obesity Medicine and Nutrition Physician Specialist. She has a primary specialty in Internal Medicine. She is the Founder and Medical Director of “Weight & Life MD,” a Center dedicated to Medical Weight Management, Nutrition, Fitness and Lifestyle located in New Jersey. She strongly believes in a personalized as well as long-term approach to treating the chronic disease of obesity and its co-morbid conditions. Nadia is also a member of the OAC’s Education Committee. 

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