Blood tests
Primary tests performed for the diagnosis of uremia are basic metabolic panel with serum calcium and phosphorus to evaluate the GFR, blood urea nitrogen and creatinine as well as serum potassium, phosphate, calcium and sodium levels. Principal abnormality is very low GFR (<30 mL/min). Uremia will demonstrate elevation of both urea and creatinine, likely elevated potassium, high phosphate and normal or slightly high sodium, as well as likely depressed calcium levels. As a basic work up a physician will also evaluate for anemia, and thyroid and parathyroid functions. Chronic anemia may be an ominous sign of established renal failure. The thyroid and parathyroid panels will help work up any symptoms of fatigue, as well as determine calcium abnormalities as they relate to uremia versus longstanding or unrelated illness of calcium metabolism. Urine tests
A 24-hour urine collection for determination of creatinine clearance may be an alternative, although not a very accurate test due to the collection procedure. Another laboratory test that should be considered is urinalysis with microscopic examination for the presence of protein, casts, blood and pH. Radioisotope tests
The most trusted test for determining GFR is iothalamate clearance. However, it may be cost-prohibitive and time-consuming. Clinical laboratories generally calculate the GFR with the modification of diet in renal disease (MDRD) formula or the  Cockcroft-Gault formula. Other
In addition, coagulation studies may indicate prolonged bleeding time with otherwise normal values. Mechanism
Uremia results in many different compounds being retained by the body. With the failure of the kidneys, these compounds can build up to dangerous levels.
In addition, infants who are given cows milk too early can develop anemia due to gastrointestinal blood loss.Children who are at risk for iron-deficiency anemia include:
Preterm infants
Low birth weight infants
Infants fed with cows milk under 12 months of age
Breastfed infants who have not received iron supplementation after age 6 months, or those receiving non-iron-fortified formulas
Children between the ages of 1 to 5 years old who receive more than 24 ounces (700 mL) of cow milk per day
Children with low socioeconomic status
Children with special health care needs
Children of Hispanic ethnicity
Children who are overweight

Blood donation
Frequent blood donors are also at risk for developing iron deficiency anemia. When whole blood is donated, approximately 200 mg of iron is also lost from the body. The blood bank screens people for anemia before drawing blood for donation. If the patient has anemia, blood is not drawn. Less iron is lost if the person is donating platelets or white blood cells. Hepcidin
Decreased levels of serum and urine hepcidin are early indicators of iron deficiency. Hepcidin concentrations are also connected to the complex relationship between malaria and iron deficiency. Mechanism
Anemia can result from significant iron deficiency. When the body has sufficient iron to meet its needs (functional iron), the remainder is stored for later use in cells, mostly in the bone marrow and liver. These stores are called ferritin complexes and are part of the human (and other animals) iron metabolism systems.