Medical causes of fatigue Some common causes of fatigue include: 1  Anemia â When you have low red blood cell counts in your bloodstream, your body has to work harder to deliver oxygen to your cells, causing fatigue.2  Iron deficiency is also associated with fatigue. Anemia â When you have low red blood cell counts in your bloodstream, your body has to work harder to deliver oxygen to your cells, causing fatigue. 2  Iron deficiency is also associated with fatigue. 3  If you're diagnosed with anemia, then it's important to understand the cause in order to correct the problem.
Occasionally, a health practitioner will look at the ratio between a person's BUN and blood creatinine to help determine what is causing these concentrations to be higher than normal. The ratio of BUN to creatinine is usually between 10:1 and 20:1.An increased ratio may be due to a condition that causes a decrease in the flow of blood to the kidneys, such as congestive heart failure or dehydration.ccasionally, a health practitioner will look at the ratio between a person's BUN and blood creatinine to help determine what is causing these concentrations to be higher than normal. The ratio of BUN to creatinine is usually between 10:1 and 20:1.
Occasionally, a health practitioner will look at the ratio between a person's BUN and blood creatinine to help determine what is causing these concentrations to be higher than normal. The ratio of BUN to creatinine is usually between 10:1 and 20:1.