Lab Testing Can Explain Your Extreme Fatigue

Written By Mila N., 30 June, 2022

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  • Feeling tired is a common complaint that we often hear, and we usually feel related to it. It can be due to many reasons, such as excessive physical activity during work or at the gym, leading a busy life and having to face stressful situations, or even feeling mentally exhausted due to lack of sleep after spending the night working or studying. However, having unexplained fatigue which hinders your productivity and interferes with you accomplishing your daily activities can be alarming and is considered a warning of some underlying disease or deficiency that your body is signaling. For this reason, it is important to address this condition before it escalates into developing a serious health condition.
  • The signs and symptoms of chronic fatigue can vary from person to person. Some common signs to look out for include unexplained muscle or joint pain, dizziness, brain fog, headache, memory and concentration problems, and headaches. Unrelenting exhaustion can be a sign of some serious underlying conditions such as diabetes, cancer, anemia, depression, or thyroid disease. Unfortunately, more often than not, lab testing for the detection of hormonal, vitamin, and mineral deficiencies is overlooked by prescribers. These tests can be useful in helping to explain the underlying reasons for someone’s constantly fatigued state.

  • Vitamin or mineral deficiency:

  • Vitamin and mineral deficiencies are possible reasons for feeling tired all the time. Specifically, lack of adequate vitamin D, vitamin B12, and iron deficiencies are among the most common causes of fatigue.

  • Vitamin D:
  • Is it no surprise that the lack of vitamin D is significant, especially among the U.S. population. Vitamin D can be acquired through direct sun exposure, from the diet, or by taking supplements. Upon exposure to vitamin D, the liver converts it into the active form called 25 hydroxyvitamin D, or 25(OH)D for it to be used by the body. That is why, a lab blood test for 25(OH)D is the most accurate way to detect vitamin D levels in your body.

  • Vitamin B12:
  • Vitamin B12, also known as cobalamin, is an important vitamin for the development and maintenance of healthy nerve and blood cells and for the formation of DNA. It is also known for its great use in boosting energy and enhancing one’s mood. The direct testing of B12 in the body, however, may not be indicative of the accurate levels of the vitamin because someone can have normal levels of vitamin B12 and still have symptoms of fatigue. More reliable markers for testing would be methylmalonic acid and homocysteine. The trends of these markers are irreversibly related to vitamin B12 levels in the body. That is, in case of vitamin B12 deficiency, methylmalonic acid and homocysteine would be elevated. A lack of sufficient vitamin B12 can be linked to a number of health conditions such as anemia, cardiovascular disease, and cognitive decline.

  • Iron:
  • Iron is an essential mineral that is needed for growth and development. It is responsible for producing red blood cells which carry oxygen from the lungs to organs and tissues. Experiencing fatigue can be due to insufficient amounts of iron. Iron deficiency is also a leading cause of the development of anemia.
  • There are several tests for detecting iron levels in the body:
  • Serum iron test: measures the amount of circulating iron in the blood.
  • Total-iron binding capacity: measures iron’s binding affinity to transferrin, a glycoprotein that helps transfer iron throughout the body. High levels of TIBC indicate high levels of free transferrin in the blood and a relatively low iron content.
  • Ferritin test: measures the amount of iron stored in the body. Low ferritin levels indicate low iron storage.

  • Thyroid hormones:
  • The thyroid gland plays a major role in regulating the body by producing hormones that affect vital body functions such as metabolism, heart rate control, and growth. The two hormones that are secreted are triiodothyronine (T3) and thyroxine (T4). A dysfunction in the thyroid gland will affect the hormone levels produced and consequently, their respective functions. Hypothyroidism, an underactive thyroid, is caused by a decline in thyroid hormones. Hyperthyroidism, on the other hand, is an overactive thyroid condition caused by an increase in thyroid hormone levels. Both thyroid dysfunctions can have fatigue as a mutual symptom experienced by a patient. Measuring T3 and T4 levels can help distinguish between hypothyroidism and hyperthyroidism and explain the reasons for fatigue.

  • Testosterone hormone:
  • Low testosterone levels in both men and women are associated with symptoms of extreme tiredness. An imbalance in testosterone hormone concentrations can lead to several dysfunctions including insomnia, depression, and loss of muscle mass. Lab testing for testosterone can help with interpreting the underlying reasons for fatigue. There are three types of testosterone lab tests that can be done: a total testosterone test, a free testosterone test, and a bioavailable testosterone test. The most common lab test performed is the total testosterone test where comprehensive levels of testosterone bound to proteins and unbound are measured.

  • Glucose test:
  • High and low blood sugar levels are both common causes of fatigue. In cases of high blood sugar levels, which can lead to developing diabetes, the body is unable to produce enough insulin to combat the spike in sugar levels, so the body resorts to creating energy from the stored fat. On the other hand, a drop in blood sugar levels due to inadequate nutrition or starvation can also deprive the body of the energy it needs to function properly. In both cases, inadequate sources of energy consequently lead to symptoms of fatigue. Lab testing for serum glucose levels is a common method to interpret a patient’s excessive tiredness and make an appropriate diagnosis for their condition.